I need help with .jar files!

Does anyone know how to set java as your default program for .jar files, because i did something stupid and set windows explorer as my default program for them. When I double click the *.jar, my cursor just flickers between "idle" and "working in background".

I am windows 7 running java SE binary (i think) jre6, don't know what update. (will find out soon)

If someone could please reply, that would be AWESOME !

Thanks,
-Dano