Configuring Eclipse to run with a specific JDK or JRE

1. Open the file eclipse.ini for editing

2. Add the two lines to specify the virtual machine to use (the bolded lines):

-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar

-vm 
C:\Program Files\Java\jdk1.6.0_29\bin\javaw.exe

--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.100.v20110502

3. Now start eclipse.

4. To make sure the changes took place go to Help > About Eclipse > Configuration Details

For more information please see:
http://help.eclipse.org/indigo/index.jsp?topic=/org.eclipse.platform.doc.user/tasks/running_eclipse.htm

http://wiki.eclipse.org/Equinox_Launcher#Finding%5Fa%5FVM.2C%5FUsing%5FJNI%5FInvocation%5For%5FExecuting%5FJava

And stackoverflow:
http://stackoverflow.com/questions/905611/how-do-i-set-eclipse-ini-vm-option