The JRWorker.exe process has nothing at all to do with Java. I don't know where you got that.
I don't know, but I'd be very suspicious of that system. Malware, disk or OS corruption, or hardware issues. The "this program did not run correctly" error message is generated by Microsoft's Application Compatibility Assistant, which should only apply to very old software (things written way previous to Windows Vista, if not earlier).
It absolutely doesn't apply to MC.
