Assuming that there is no response to CTRL+ALT+DEL, then the answer is no. Computers can "freeze" for a number of reasons, but with a properly configured XP system, it is most likely that the CPU is running too hot. This will show up when the CPU load is high. Try this: Open Windows Media Player 9, click "File", then "New Playlist". Sit back and wait a couple of minutes. If the system freezes, you've got a heat problem. For some reason, when the playlist is open, WMP uses nearly 100% CPU. If this causes your system to freeze, check the CPU fan and heatsink mounting
Anyway to un-freeze without rebooting?