Quite a while back, Javacool had recommended that before running a defrag, Spyware Guard's options should be unticked, options saved, and SG shut down (exited, via its menu) before doing a defrag. Apparently there'd been some problems reported defragging with SG fully active. An addition to this, if I may -- if you also have Spybot S&D, and have its TeaTimer active, exit TeaTimer before doing anything to SG. I found out the hard way tonight that TeaTimer objects strenuously to the registry changes involved, and keeps blocking them. And after the defrag, restart and reactivate SG before reactivating TeaTimer, for the same reason.