I am trying to get my first taste of Android development using Eclipse. I ran into this problem when trying to run Eclipse, having installed version 4.2 only minutes ago.
If you install a 64-bit Eclipse version on a PC with a 32-bit JRE this is guaranteed to occur.
So the solution is quite straightforward: You need to synchronise them by updating either one. This shall happen when downloading Oracle Fusion middleware and Eclipse expects a 32-bit environment while your JRE is 64-bit and your JAVA home is pointing to a 64-bit JDK.