in you file explore /Tools /Foder Options /File Types , edit Executable Jar File
what action will be do compeletely decided by you, note the parameter , generally ,if no paramter (%1) ,when you double click the file , there is no means let your action connected with the concrete jar instance.
Help. .JAR can't run. When I click the file.jar, the harddisk will run for a while. Then, nothing happend. I click the JAVAW.exe in the \JAVA1.2.2\BIN, it's the same. Nothing will happen except the harddisk running.