How to install JDK 1.7.0 and how to set path and classpath variables

How to Install

Java Development Kit (JDK) 1.7 or SE 7, which is freely available from Sun Microsystems (now part of Oracle), is needed for writing Java programs. 

JDK can be downloaded from the Java mother site @ http://java.sun.com 

(or)  http://www.oracle.com/technetwork/java/index.html).

How To Install JDK 1.7.0

JDK or JRE?

JRE (Java Runtime Environment) is needed for running Java programs. 

JDK (Java Development Kit), which includes JRE plus the development tools (such as compiler and debugger), is need for writing Java programs.

 Since you are supposed to write Java Programs, install JDK (which includes JRE).

STEP 0: Un-install Older Version of JDK/JRE 

If you have previously installed older version of JDK/JRE, un-install them.

 Run "Control Panel" ⇒ "Program and Features" ⇒ Un-install programs such as "Java SE Development Kit" and "Java SE Runtime". (If you are not sure whether you have older versions of JDK, check!)

STEP 1: Download JDK

1. Goto Java SE download site @ http://www.oracle.com/technetwork/java/javase/downloads/index.html.
2. Click the "Download" button under "JDK" of "Java SE 7".
3. Choose your operating platform, e.g., Windows x86 (for 32-bit Windows OS - "jdk-7u2-windows-i586.exe" 84MB); or Windows x64 (for 64-bit Windows OS).

STEP 2: Install JDK/JRE

Run the downloaded installer, which installs both the JDK (Java Development Kit) and JRE (Java Runtime). By default, the JDK and JRE will be installed into directories "C:\Program Files\java\jdk1.7.0" and "C:\Program Files\java\jre7", respectively. 

here i am refering to  JDK installed directory as <JAVA_HOME>

After downloading  JDK 1.7.0,just click on it ,you will get like this ,as shown below

 click on run

 click next 

click next 

after this window,u will observe like this

you have installed successfully now,click finish.

Now we have to set PATH and CLASS PATH  variables  inorder to compile or execute java .

These are said to be environment variables.

click My computer ==> properties ==>advanced,       following window will be opened like this

Now click Environment Variables, here variables are divided into two sections 

User variables : whenever it is modified the corresponding language only effected.  

Ex: Class path , in this example class variables are always for .class values 

System variables : whenever it is modified not only a single language,  corresponding  all languages are  only effected. 

Ex:path, here the variable is searching for .exe files

 click new button

variable name = classpath

variable value =  C:\Program Files\Java\jdk1.7.0

one more environment variable ,we have to set for Java home directory similar to path and 

class path.

click new button

for java home

variable name = java_home

variable value =  C:\Program Files\Java\jdk1.7.0.

Now click ok for twice. 

now for system variables ,let us set path

click new

variable name = path

variable value = C:\Program Files\Java\jdk1.7.0\bin







IF U WANT TO VERIFY JAVA IS INSTALLED SUCCESSFULLY OR NOT ,JUST GO TO COMMAND PROMT,TYPE javac if u see java compiling commands like below ,then u have installed it successfully.