I've recently had installed by a friend of mine (a university electronics lecturer) a Microsoft optical mouse and receiver (replacements for a wired mouse). If I am working but inactive for a few minutes when I return to reposition the pointer, or whatever, to recommence work if I accidentally move the mouse sideways instead of forward or backward, and no matter what program I am running, the latter is instantly terminated and I am returned to the desktop. This has happened to me 3 or 4 times in the last 3 weeks (once during a defrag) and I have lost work as a result. The optical receiver (Microsoft V2.0) is wired and not connected via USB. Any helpful suggestions would be extremely welcome. My installer friend's suggestions have failed to overcome the problem to date.