Normally after installing Java, there will be an association between .jar and the javaw.exe. This enables the executable jar to be opened on double click. You can check the association by going to Control Panel -> Programs -> Default Programs -> Associate a file type or protocol with a program.The default program of a file type can be changed in this dialog. However sometimes there are cases where the file association for .jar may be altered after a third party application installed. The executable jar may not be able to be started normally post that and it still doesn't work eve...