Moved this post from windows issues. Thought there was something more seriously wrong with my pc because I didnt realize when my hand was tapping the little volume wheel on the front of the computer. Doing so makes the system lock up. The mouse cursor still moves around the screen but clicking on things does not do anything (including telling me that it isnt responding) -- the windows key still works, and pulls up the start menu, but the arrow keys and the mouse cannot select any buttons on it. alt + tab does not work, but ctrl + alt +del does pull up the task manager, but I can't actually click or select anything on it. The only real change I made to the system (immediately after buying it) was removing vista and installing xp. The system is designed for vista, but seems to run fine on xp, and hasn't been a problem before. I've got a soundcard driver for xp that works fine, the sound works fine, dxdiag says it's ok. Is this an issue of compatibility with xp or some kind of fatal hardware problem? The volume wheel worked fine a week ago, in xp.