I'm having a problem with my laptop, running Windows XP service pack 2. It's an alienware (i forget what model, it's a couple years old) and up until recently, no problems whatsoever.
About a week ago however, i was trying to play Worms World Party, and couldn't manage to move using the keyboard. After going through the options, trying to find the problem in keybindings, i finally gave up and started trying to quit (alt-f4). this didn't work. I started to push every button on my keyboard, trying to determine if it was a hardware problem. to my surprise, pushing the alt button and an arrow key allowed me to move. release alt, no movement. push alt, movement!
Hoping it's a freak problem, i restarted the computer. Problem persists. Loading up Age of Empires 2, keyboard works fine. As with Dawn of War, Fable, and Diablo 2. So far, the only two games i've been able to duplicate the problem are with Worms World Party, and the N-game (flash game where you play as a ninja).
I've played both WWP and the N-game frequently, they only recently started acting up. No new software installed, no new hardware, no internet connection and virus scan is clean.
My coworker (we're deployed) is having a similar problem with his laptop, an Asus something-or-other running Vista. We haven't tried WWP or the N-game on his, but he's having the problem in Bioshock, not being able to move unless he holds the alt key. Once again, no new hardware, but he's installed a couple new games in the past two weeks. No internet connection for him either, and virus scan good. We've swapped movies via an external hard drive, but that's the only interface the computers have had, and the virus software can't find anything bad on that drive, either.

Does anyone have any advice over what this could be? Some setting that somehow got changed on both our computers? Google hasn't helped, nor has the search function on this or any other tech forum i've found.
Any suggestions would be welcome, thanks!

If the problem exists only in those two games, then it rules out out a system or hardware issue. Have you considered uninstalling those games and reinstalling?