Here's a weird situation for you. Yesterday one of my co-worker's had her PC go into locked mode (control-alt-delete then select Lock Computer) without her causing it, and when she tried to unlock it the password was different to what it had been earlier. I managed to reset her password from the server and get her in again, but its baffling me as to how this could have happened. I immediately installed Spybot Search & Destroy, did a quick update then scanned the system, during which a number of spywares were found.