Try win32 mutex objects with Win32::Mutex. Have app A obtain a mutex. If app B can obtain the same mutex, then app A is not running.

MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"

I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).

** The third rule of perl club is a statement of fact: pod is sexy.