I got a new toshiba satellite p200 laptop last week. It ran fine for a week, and now, with no apparently warning, at random times (sometimes 30 minutes apart, sometimes hours apart) the system locks 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. The pc is not hot or seems overheated in any way. Is this possibly a hardware compatibility issue, or a memory issue, or what? Very confusing.

Thanks for the help,

A week or two old? That is a warranty job. You are paying for it, so get some value.