I am also having issues with adding purge to Windows 7. I tried a couple of things suggested, but they don't seem to work long term. Some of my users get an error and other don't get it to run at all.
Windows 7 is not as easy as the old XP when it comes to adding purge to the right click menu. I still don't have a solution.
"Too many people walk around like Clark Kent, because they don't realize they can Fly like Superman"