I installed OpenWorkbench and it failed to start with JRE 1.7. I uninstalled Java, removing all traces from the registry and reinstalled, this time with v1.8. OWB still fails to start. The JRE bin dir is on my path and the registry points to it correctly. The only thing that I can think of, assuming OWB is correctly processing the information, is that I'm running on 64-bit Win7 with a 64-bit JRE, but OWB requires 32-bit versions of one or the other.