I have had this problem for a year or so and I have spent so long trying to fix it I feel like I am going to fucking cry.
I have the latest java and JDK. I can not run any .jar files. I can play stuff that uses java through my browser but cannot run a program off my hard drive. I am using vista.
Let me explain it in a simple form:
1. Father downloaded new java I think and maybe something else like windows update.
2. When I try to run my .jar files it says it doesnt know what to open it with.
3. Ages trying to fix it.
4. .jar files open a black command prompt box with text for a split second then it closes instantly.
5. uninstalled all my java staff again.
6. Reinstalled the newest Java and JDK.
7. See step 4.

