Eclipse : A java Runtime Environment (JRE) or Java Development kit (JDK) must be available

Error: A java Runtime Environment (JRE) or Java Development kit (JDK)
must be available in order to run Eclipse. No Java virtual machine was found
after searching the following locations: D:\eclipse\jre\javaw.exe javaw.exe
in your current PATH.

If you get the above message when you try to run eclipse on you Computer then this can be because of various reasons,

Is Java Runtime Environment (JRE) installed ?

This is the first thing you must check. If not then you must download it and get it installed (but do check the eclipse version 64 bit or 32 bit and download the appropriate setup)

64bit/32bit version issue!

If you have a 64bit Operating System then you must have 64bit installation of Java and Eclipse or 32bit installation of Java and Eclipse (odd combinations will give such errors)

If you have a 32bit Operating System then you must have 32bit installation of Java as well as Eclipse.

Invalid Java Environment Variable PATH setup!

Right click on My Computer icon -> Properties -> Advance System Settings -> Environment Variables

Go to System Variables -> Path, Click on Edit

Now click on new, add the following,

Variable Name : JAVA_HOME
Variable Value : C:/Program files/java/jdk_path/ (path to your jdk)
Under Variable Value itself add a semicolon ; and add %JAVA_HOME%/bin
Example : C:\Program Files (x86)\Java;%JAVA_HOME%\Java\jdk1.6.0_14\bin

Correct eclipse.ini setting up for javaw.exe

Under the eclipse folder you would see eclipse.ini file, check the path for javaw.exe,

eclipse -vm C:\Program Files\jdk\jre\bin\javaw.exe

Hope it helps someone! Happy Coding :)