“Could not find the main class” when double-clicking .jar file
Perhaps your file associations got messed up. At the command prompt, try running ftype | find “jarfile” On my 64-bit Windows 7 computer, that shows jarfile=”C:\Program Files (x86)\Java\jre6\bin\javaw.exe” -jar “%1″ %* You can also change it with ftype: ftype jarfile=”C:\Program Files (x86)\Java\jre6\bin\javaw.exe” -jar “%1” %*