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.
I had a similar error after installing Java 8 on my Windows 7 system, 64 bit system.
Changing environment variables, etc. did not help. So I tried to remove the Java Update 8, but that too did not help. Downloading and installing the 64-bit version of Java 8 SDK fixed my problem. I hope this helps.