Operators in java

Operator is a special symbol that is used to perform operations. There are many types of operators in java such as unary operator, arithmetic operator, relational operator, shift operator, bitwise operator, ternary operator and assignment operator.




                    Precedence of Operators

Operators	Precedence
postfix	expr++ expr--
unary	++expr --expr +expr -expr ~ !
multiplicative	* / %
additive	+ -
shift	<< >> >>>
relational	< > <= >= instanceof
equality	== !=
bitwise AND	&
bitwise exclusive OR	^
bitwise inclusive OR	|
logical AND	&&
logical OR	||
ternary	? :
assignment	= += -= *= /= %= &= ^= |= <<= >>= >>>=

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Useful Programs:

There is given some useful programs such as factorial number, prime number, fibonacci series etc.

It is better for the freshers to skip this topic and come to it after OOPs concepts.

1) Program of factorial number.

class Operation{

 static int fact(int number){
  int f=1;
  for(int i=1;i<=number;i++){
  f=f*i;
  }
 return f;
 }

 public static void main(String args[]){
  int result=fact(5);
  System.out.println("Factorial of 5="+result);
 }
}

---

2) Program of fibonacci series.

class Fabnoci{
 
  public static void main(String...args)
  {
    int n=10,i,f0=1,f1=1,f2=0;
	for(i=1;i<=n;i++)
	{
	  f2=f0+f1;
	  f0=f1;
	  f1=f2;
          f2=f0;
          System.out.println(f2);
	}
	
   }
 }

---

3) Program of armstrong number.

class ArmStrong{
  public static void main(String...args)
  {
    int n=153,c=0,a,d;
	d=n;
	while(n>0)
	{
	a=n%10;
	n=n/10;
	c=c+(a*a*a);
	}
	if(d==c)
	System.out.println("armstrong number"); 
	else
    System.out.println("it is not an armstrong number"); 
	
   }
}

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4) Program of checking palindrome number.

class Palindrome
{
   public static void main( String...args)
  {
   int a=242;
   int  n=a,b=a,rev=0;
   while(n>0)
   {
     a=n%10;
     rev=rev*10+a;
     n=n/10;
   }
   if(rev==b)
   System.out.println("it is Palindrome");
   else
   System.out.println("it is not palinedrome");
  
  }
}

---

5) Program of swapping two numbers without using third variable.

class SwapTwoNumbers{
public static void main(String args[]){
int a=40,b=5;
a=a*b;
b=a/b;
a=a/b;

System.out.println("a= "+a);
System.out.println("b= "+b);

}
}

---

6) Program of factorial number by recursion

class FactRecursion{

static int fact(int n){
if(n==1)
return 1;

return n*=fact(n-1);
}

public static void main(String args[]){

int f=fact(5);
System.out.println(f);
}
}

Unicode System

Unicode is a universal international standard character encoding that is capable of representing most of the world's written languages.

Why java uses Unicode System?

Before Unicode, there were many language standards:

ASCII (American Standard Code for Information Interchange) for the United States. ISO 8859-1 for Western European Language. KOI-8 for Russian. GB18030 and BIG-5 for chinese, and so on.

This caused two problems: A particular code value corresponds to different letters in the various language standards. The encodings for languages with large character sets have variable length.Some common characters are encoded as single bytes, other require two or more byte.

To solve these problems, a new language standard was developed i.e. Unicode System.

In unicode, character holds 2 byte, so java also uses 2 byte for characters.

lowest value:\u0000

highest value:\uFFFF

Variable and Datatype in Java

1. Variable
2. Types of Variable
3. Data Types in Java

In this page, we will learn about the variable and java data types. Variable is a name of memory location. There are three types of variables: local, instance and static. There are two types of datatypes in java, primitive and non-primitive.

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Variable

Variable is name of reserved area allocated in memory.

int data=50;//Here data is variable

Types of Variable

There are three types of variables in java local variable instance variable static variable

Local Variable

A variable that is declared inside the method is called local variable.

Instance Variable

A variable that is declared inside the class but outside the method is called instance variable . It is not declared as static.

Static variable

A variable that is declared as static is called static variable. It cannot be local.

We will have detailed learning of these variables in next chapters.

Example to understand the types of variables

class A{

int data=50;//instance variable

static int m=100;//static variable

void method(){
int n=90;//local variable
}

}//end of class

---

Data Types in Java

In java, there are two types of data types primitive data types non-primitive data types

Data Type	Default Value	Default size
Boolean	false	1 bit
char	'\u0000'	2 byte
byte	0	1 byte
short	0	2 byte
int	0	4 byte
long	0L	8 byte
float	0.0f	4 byte
double	0.0d	8 byte

Why char uses 2 byte in java and what is \u0000 ?

because java uses unicode system rather than ASCII code system. \u0000 is the lowest range of unicode system.To get detail about Unicode see below.

JVM (Java Virtual Machine)

1. Java Virtual Machine
2. Internal Architecture of JVM
3. Classloader
4. Class Area
5. Heap Area
6. Stack Area
7. Program Counter Register
8. Native Method Stack
9. Execution Engine

JVM (Java Virtual Machine) is an abstract machine.It is a specification that provides runtime environment in which java bytecode can be executed.

JVMs are available for many hardware and software platforms (i.e.JVM is plateform dependent).

The JVM performs four main tasks: Loads code Verifies code Executes code Provides runtime environment

JVM provides definitions for the: Memory area Class file format Register set Garbage-collected heap Fatal error reporting etc.

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Internal Architecture of JVM

Let's understand the internal architecture of JVM. It contains classloader, memory area, execution engine etc.

1) Classloader:

Classloader is a subsystem of JVM that is used to load class files.

2) Class(Method) Area:

Class(Method) Area stores per-class structures such as the runtime constant pool, field and method data, the code for methods.

3) Heap:

It is the runtime data area in which objects are allocated.

4) Stack:

Java Stack stores frames.It holds local variables and partial results, and plays a part in method invocation and return.

Each thread has a private JVM stack, created at the same time as thread.

A new frame is created each time a method is invoked. A frame is destroyed when its method invocation completes.

5) Program Counter Regiser:

PC (program counter) register. It contains the address of the Java virtual machine instruction currently being executed.

6) Native Method Stack:

It contains all the native methods used in the application.

7) Execution Engine:

It contains:

1) A virtual processor

2) Interpreter:Read bytecode stream then execute the instructions.

3) Just-In-Time(JIT) compiler:It is used to improve the performance.JIT compiles parts of the byte code that have similar functionality at the same time, and hence reduces the amount of time needed for compilation.Here the term ?compiler? refers to a translator from the instruction set of a Java virtual machine (JVM) to the instruction set of a specific CPU.

Difference between JDK,JRE and JVM

1. Brief summary of JVM
2. Java Runtime Environment (JRE)
3. Java Development Kit (JDK)

Understanding the difference between JDK, JRE and JVM is important in Java. We will have brief overview of JVM here. If you want to gain the detailed knowledge of JVM, move to the next page. Firstly, let's see the basic differences between the JDK, JRE and JVM.

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JVM

JVM (Java Virtual Machine) is an abstract machine.It is a specification that provides runtime environment in which java bytecode can be executed.

JVMs are available for many hardware and software platforms (i.e.JVM is plateform dependent).

The JVM performs four main tasks: Loads code Verifies code Executes code Provides runtime environment

---

JRE

JRE is an acronym for Java Runtime Environment.It is used to provide runtime environment.It is the implementation of JVM.It physically exists.It contains set of libraries + other files that JVM uses at runtime.

Implementation of JVMs are also actively released by other companies besides Sun Micro Systems.

---

JDK

JDK is an acronym for Java Development Kit.It physically exists.It contains JRE + development tools.

How to set path of JDK in Windows:

Posted by Nishanth Singamala

1. How to set path of JDK in Windows OS
   1. Setting Temporary Path of JDK
   2. Setting Permanent Path of JDK
2. How to set path of JDK in Linux OS
3. 
   

Path is required for using tools such as javac, java etc. If you are saving the java file in jdk/bin folder, path is not required.But If you are having your java file outside the jdk/bin folder, it is necessary to set path of JDK. There are two ways to set path of JDK: temporary permanent

1)Setting temporary Path of JDK in Windows:

For setting the temporary path of JDK, you need to follow these steps:

Open command prompt copy the path of bin folder write in command prompt: set path=copied path

For Example:

set path=C:\Program Files\Java\jdk1.6.0_23\bin
      

Let's see it in the figure given below:

---

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2)Setting Permanent Path of JDK in Windows:

For setting the permanent path of JDK, you need to follow these steps:

• Go to MyComputer properties -> advanced tab -> environment variables -> new tab of user variable -> write path in variable name -> write path of bin folder in variable value -> ok -> ok -> ok

For Example:

1)Go to MyComputer properties

2)click on advanced tab

3)click on environment variables

4)click on new tab of user variables

5)write path in variable name

6)Copy the path of bin folder

7)paste path of bin folder in variable value

8)click on OK button

9)click on OK button

Now your permanent path is set.You can now execute any program of java from any drive.

---

Setting Path in Linux OS

Setting the path in Linux OS is same as setting the path in the Windows OS. But here we use export tool rather than set. Let's see how to set path in Linux OS:

export PATH=$PATH:/home/jdk1.6.01/bin/
      

Here, we have installed the JDK in the home directory under Root (/home).

Internal Details of Hello Java Program

Posted by Nishanth Singamala

1. Internal Details of Hello Java

In the previous page, we have learned about the first program, how to compile and how to run the first java program. Here, we are going to learn, what happens while compiling and running the java program. Moreover, we will see some quesitons based on the first program.

What happens at compile time?

At compile time, java file is compiled by Java Compiler (It does not interact with OS) and converts the java code into byte-code.

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What happens at runtime?

At runtime, following steps are performed:

Classloader: is the subsystem of JVM that is used to load class files.

Bytecode Verifier: checks the code fragments for illegal code that can violate accesss right to objects.

Interpreter: read bytecode stream then execute the instructions.

---

Q)Can you save a java source file by other name than the class name?

Yes, like the figure given below illustrates:

To compile:	javac Hard.java
To execute:	java Simple

---

Q)Can you have multiple classes in a java source file?

Yes, like the figure given below illustrates:

Hello Java Example

1. Requirements for creating Hello Java Example
2. Creating Hello Java Example
3. Resolving javac not recognized exception

In this page, we will learn how to write the hello java program. Creating hello java example is too easy. Here, we have created a class named Simple that contains only main method and prints a message hello java. It is the simple program of java.

Requirement for Hello Java Example

For executing any java program, you need to create the java program. install the JDK if you don't have installed it, download the JDK and install it. set path of the bin directory under jdk. compile and execute the program.

---

Creating hello java example

Let's create the hello java program:

class Simple{
public static void main(String args[]){
     System.out.println("Hello Java")
    }
}

save this file as Simple.java

To compile:	javac Simple.java
To execute:	java Simple

Output:Hello Java

---

Understanding first java program

Let's see what is the meaning of class, public, static, void, main, String[], System.out.println().

• class is used to declare a class in java.
• public is an access modifier which represents visibility, it means it is visible to all.
• static is a keyword, if we declare any method as static, it is known as static method. The core advantage of static method is that there is no need to create object to invoke the static method. The main method is executed by the JVM, so it doesn't require to create object to invoke the main method. So it saves memory.
• void is the return type of the method, it means it doesn't return any value.
• main represents startup of the program.
• String[] args is used for command line argument. We will learn it later.
• System.out.println() is used print statement.

---

To write the simple program, open notepad and write simple program as displayed below:

As displayed in the above diagram, write the simple program of java in notepad and saved it as Simple.java. To compile and run this program, you need to open command prompt by start -> All Programs -> Accessories -> command prompt.

To compile and run the above program, go to your current directory first; my current directory is c:\new . Write here:

To compile:	javac Simple.java
To execute:	java Simple

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Resolving an exception "javac is not recognized as an internal or external command" ?

If there occurs a problem like displayed in the below figure, you need to set path. Since DOS doesn't know javac or java, we need to set path. Path is not required in such a case if you save your program inside the jdk/bin folder. But its good approach to set path. Click here for How to set path in java.

  

Features of Java

Posted By Nishanth Singamala

There is given many features of java. They are also called java buzzwords.

1. Features of Java
   1. Simple
   2. Object-Oriented
   3. Platform Independent
   4. secured
   5. Robust
   6. Architecture Neutral
   7. Portable
   8. High Performance
   9. Distributed
   10. Multi-threaded

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Simple

Java is simple in the sense that:

syntax is based on C++ (so easier for programmers to learn it after C++).

removed many confusing and/or rarely-used features e.g., explicit pointers, operator overloading etc.

No need to remove un-referenced objects because there is Automatic Garbage Collection in java.

---

Object-oriented

Object-oriented means we organize our software as a combination of different types of objects that incorporates both data and behavior.

Object-oriented programming(Oops) is a methodology that simplify software development and maintenance by providing some rules.

Basic concepts of Oops are:

Object Class Inheritance Polymorphism Abstraction Encapsulation

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Platform Independent

A platform is the hardware or software environment in which a program runs. There are two types of platforms software-based and hardware-based. Java provides software-based platform. The Java platform differs from most other platforms in the sense that it's a software-based platform that runs on top of other hardware-based platforms.It has two components: Run time Environment API(Application Programming Interface)

Java code can be run on multiple platforms e.g.Windows,Linux,Sun Solaris,Mac/OS etc. Java code is compiled by the compiler and converted into byte code. This byte code is a platform independent code because it can be run on multiple platforms i.e. Write Once and Run Anywhere(WORA).

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Secured

Java is secured because:

No explicit pointer Programs run inside virtual machine sandbox.

Classloader- adds security by separating the package for the classes of the local file system from those that are imported from network sources. Bytecode Verifier- checks the code fragments for illegal code that can violate accesss right to objects. Security Manager- determines what resources a class can access such as reading and writing to the local disk.

These security are provided by java language. Some sucurity can also be provided by application developer through SSL,JAAS,cryptography etc.

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Robust

Robust simply means strong. Java uses strong memory management. There are lack of pointers that avoids security problem. There is automatic garbage collection in java. There is exception handling and type checking mechanism in java. All these points makes java robust.

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Architecture-neutral

There is no implementation dependent features e.g. size of primitive types is set.

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Portable

We may carry the java byte-code to any platform.

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High-performance

Java is faster than traditional interpretation since byte code is "close" to native code still somewhat slower than a compiled language (e.g., C++)

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Distributed

We can create distributed applications in java. RMI and EJB are used for creating distributed applications. We may access files by calling the methods from any machine on the internet.

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Multi-threaded

A thread is like a separate program, executing concurrently. We can write Java programs that deal with many tasks at once by defining multiple threads. The main advantage of multi-threading is that it shares the same memory. Threads are important for multi-media, Web applications etc.

History of Java

Posted By Nishanth Singamala

• Brief history of Java
• Java Version History

Java history is interesting to know. Java team members (also known as Green Team), initiated a revolutionary task to develop a language for digital devices such as set-top boxes, televisions etc.
At that time, it was a advanced concept for the green team. But, it was good for internet programming. Later, Netscape Navigator incorporated Java technology.

James Gosling

Currently, Java is used in internet programming, mobile devices, games, e-business solutions etc. Let's see the major points that describes the history of java.


1) James Gosling, Mike Sheridan, and Patrick Naughton initiated the Java language project in June 1991. The small team of sun engineers called Green Team.

2) Originally designed for small, embedded systems in electronic appliances like set-top boxes.

3) Firstly, it was called "Greentalk" by James Gosling and file extension was .gt.

4) After that, it was called Oak and was developed as a part of the Green project.

5) Why Oak? Oak is a symbol of strength and choosen as a national tree of many countries like U.S.A., France, Germany, Romania etc.

6) In 1995, Oak was renamed as "Java" because it was already a trademark by Oak Technologies.

7) Why they choosed java name for java language? The team gathered to choose a new name. The suggested words were "dynamic", "revolutionary", "Silk", "jolt", "DNA" etc. They wanted something that reflected the essence of the technology: revolutionary, dynamic, lively, cool, unique, and easy to spell and fun to say.
According to James Gosling "Java was one of the top choices along with Silk". Since java was so unique, most of the team members preferred java.

8) Java is an island of Indonesia where first coffee was produced (called java coffee).

9) Notice that Java is just a name not an acronym.

10) Originally developed by James Gosling at Sun Microsystems (which is now a subsidiary of Oracle Corporation) and released in 1995.

11) In 1995, Time magazine called Java one of the Ten Best Products of 1995.

12) JDK 1.0 released in(January 23, 1996).

Java Version History

There are many java versions that has been released.

1. JDK Alpha and Beta (1995)
2. JDK 1.0 (23rd Jan, 1996)
3. JDK 1.1 (19th Feb, 1997)
4. J2SE 1.2 (8th Dec, 1998)
5. J2SE 1.3 (8th May, 2000)
6. J2SE 1.4 (6th Feb, 2002)
7. J2SE 5.0 (30th Sep, 2004)
8. Java SE 6 (11th Dec, 2006)
9. Java SE 7 (28th July, 2011)

Java - What, Where and Why?

Posted By Nishanth Singamala

1. Java - What, Where and Why?
2. What is Java
3. Where Java is used
4. Java Applications

Java technology is wide used currently. Let's start learning of java from basic questions like what is java, where it is used, what type of applications are created in java and why use java?

What is Java?

Java is a programming language and a platform.
Platform Any hardware or software environment in which a program runs, known as a platform. Since Java has its own Runtime Environment (JRE) and API, it is called platform.

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Where it is used?

According to Sun, 3 billion devices run java. There are many devices where java is currently used. Some of them are as follows:

1. Desktop Applications such as acrobat reader, media player, antivirus etc.
2. Web Applications such as irctc.co.in, javatpoint.com etc.
3. Enterprise Applications such as banking applications.
4. Mobile
5. Embedded System
6. Smart Card
7. Robotics
8. Games etc.

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Types of Java Applications

There are mainly 4 type of applications that can be created using java:

1) Standalone Application

It is also known as desktop application or window-based application. An application that we need to install on every machine such as media player, antivirus etc. AWT and Swing are used in java for creating standalone applications.

2) Web Application

An application that runs on the server side and creates dynamic page, is called web application. Currently, servlet, jsp, struts, jsf etc. technologies are used for creating web applications in java.

3) Enterprise Application

An application that is distributed in nature, such as banking applications etc. It has the advantage of high level security, load balancing and clustering. In java, EJB is used for creating enterprise applications.

4) Mobile Application

An application that is created for mobile devices. Currently Android and Java ME are used for creating mobile applications.

Do You Know ?

What is the difference between JRE and JVM ? What is the purpose of JIT compiler ? Can we save the java source file without any name ? Why java uses the concept of unicode system ?

What we will learn in Basics of Java ?

History of java Features of java Simple Program of Java Internal of Hello Java Program How to set path in Windows OS Difference between JDK, JRE and JVM Internal Details of JVM Variable and Data Type Unicode System Operators

How to Change the ICON of an EXECUTABLE file

 Posted by Nishanth Singamala

Some times it becomes necessary to change the icon of an executable file so that the file gets a new appearance. Many of the tools such as TuneUP Winstyler does this job by adjusting the Windows to display a custom icon to the user. But, in reality if the file is carried to a different computer, then it shows its original icon itself.

This means that in order to permanently change the icon, it is necessary to modify the executable file and embed the icon inside the file itself. When this is done the executable file’s icon is changed permanently, so that even if you take file to a different computer it show’s a new icon.

For this purpose I have found a nice tool which will modidify the executable file and embed the icon of your choice into the file itself. ie: The tool changes the icon of the executable file permanently.

How to Change the Executable File Icon?

Here is a step-by-step instruction on how to use this tool to change the icon of any EXE file:

1. Go to www.shelllabs.com and download the trial version of IconChanger and install it (Works on XP, Vista and Win 7).
2. Run the IconChanger program from Start -> All Programs and you should see an interface as shown below:
   
3. Now you will see a window stating that “Choose an object whose icon you want to change”. Click on the “OK” button.
4. Now select the executable file for which you wish to change the icon.
5. Icon changer will automatically search for all the icons on your “C:\ drive” so that you can select any one of those. If your desired icon is not shown in the window, you may paste the path of your icon file in the field which says “Search icons in” so that your desired icon gets displayed.
6. Select the ICON of your choice and click on Set button.
7. Now a popup window will appear and ask you to select from either of these two options.
   • Change embeded icon.
   • Adjust Windows to display custom icon.
8. Select the first option (Change embedded icon). You are done. The icon gets changed.

I hope you like this post. Pass your comments in case if you have any queries or clarifications.

How to Hack Windows Vista Base Score

 Posted by Nishanth Singamala

If you are a Windows Vista user then you are very likely to be familiar with the concept of Base Score. This score is calculated based on the computer’s hardware and software configuration. This score act’s as a rating to your PC. If you have a too low base score then don’t worry. Hacking Windows Vista’s so called Base Scoreis very easy. It is possible to hack this score in just a few minutes. Here are the snapshots of my own system. Actually my system’s base score is 3.7. But I have brought it up to 9.5 with this small hack. This can be done for your computer too!

Here is a step-by-step instruction to hack the base score of Windows Vista:

1. Type the following command in the “Run” dialog box:
   %systemroot%\Performance\WinSAT\DataStore
2. You should see a .xml file with Assessment (Formal).WinSAT as filename.
3. Right-click it and select open with ‘Wordpad’ (Not notepad!)
4. On line 12, you should see something like the following:
   <SystemScore>9.5</SystemScore>
   <MemoryScore>9.5</MemoryScore>
   <CpuScore>9.5</CpuScore>
   <CPUSubAggScore>9.5</CPUSubAggScore>
   <VideoEncodeScore>5.5</VideoEncodeScore>
   <GraphicsScore>9.5</GraphicsScore>
   <GamingScore>9.5</GamingScore>
   <DiskScore>9.5</DiskScore>
5. You can enter any number in the place where I have written 9.5. But the number should be less than 10.
6. Once you have entered the number of your choice save the file and close it.
7. That’s it. You have successfully altered your Windows Vista base score. No restart is required.

Please note that this trick will neither improve the performance of your system nor will make your PC compatible to run Windows Aero UI. This is just a hack to display a bigger base score.

How to Completely Erase a Hard Disk Drive

 Posted by Nishanth Singamala

A new year has begun and perhaps you have decided to perform a system upgrade or get rid of your old computer system and purchase a new one. But, before you sell or donate your old computer, it is very much necessary tocompletely erase your hard disk drive.

Yes, every one of us are aware of this fact and so, we delete the contents of the hard disk either by using the DELETE key on our keyboard or by Formatting the hard disk.

Deleting and Formatting – Just Not Secure Enough!

But the fact is, the data will still be on the hard disk even after deleting it or formatting the hard disk. Using the delete key on your keyboard will only remove the shortcuts to the files making them invisible to users. Deleted files still reside on the hard drive and a quick Google search will show many options for system recovery software will allow anyone to reinstate that data.

Formatting the hard drive is a bit more secure way to erase the hard disk. Formatting a disk will not erase the actual data on the disk but only the address tables pointing to the data are dropped. It makes it much more difficult to recover the files. However, a computer specialist would be able to recover most or all the data that was on the disk before the reformat. For those who accidentally reformat a hard disk, being able to recover most or all the data that was on the disk is a good thing. However, if you’re preparing a system for retirement to charity or any other organization, this obviously makes you more vulnerable to data theft.

Completely Erase the Hard Disk through Disk Wiping:

So it is necessary for us to use a 100 percent secure way to erase the data from the hard disk drive. This way of securely erasing the data is called Disk Wiping. Disk wiping is a secure method of ensuring that data, including company and individually licensed software on your computer and storage devices is irrecoverably deleted before recycling or donating the equipment. Because previously stored data can be brought back with the right software and applications, the disk wiping process will actually overwrite your entire hard drive with data, several times. Once you format you’ll find it all but impossible to retrieve the data which was on the drive before the overwrite. The more times the disk is overwritten and formatted the more secure the disk wipe is.

There are a variety of disk wiping products available that you can purchase, or freely downloaded online to perform more secure disk wipes. One of my favorite disk wiping software is:

WipeDrive/ WipeDrive Professional

You have to use this tool by burning the iso image file onto a CD or by using a floppy disk. After burning this tool you have to boot your PC and follow the screen instructions to completely wipe out the data from your hard disk drive.

Display Legal Notice on Windows Startup

 Posted by Nishanth Singamala

If your PC has multiple users or you have your PC on a public place, then you can nowdisplay legal notice to every user before they log in to your PC. This legal notice will be displayed on the Logon screen at every startup just before the Desktop is loaded.

Using this way, you can tell your friends or give a warning to the users about the DO’s and DON’ts in your computer when they use it in your absence. You can do this pretty easily just by using a small registry hack.

Steps to Display Legal Notice on Startup:

1. Go to Start -> Run, type regedit and hit ENTER.
2. Navigate to the following key in the registry:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
3. On the right side pane look for “legalnoticecaption“, double click on it and enter the desired Legal Notice Caption.
   Next below this look for “legalnoticetext” and enter the desired Legal Notice Text. The legal notice text can be up to a page in its size so that it can include a set of do’s and dont’s for your computer.
4. After you do this just restart your computer and upon the next startup you can see the legal notice information for your computer. This trick works on Windows XP, Vista and Windows 7 as well.

I hope you enjoy this post! Pass your comments.