PC Blowup

HELP!!!
What is causing this problem and how do I fix it? Using Win 2000 Pro on a peer to peer network with a Dell Demension 700R. The reoccuring problem is: occassionally my screen goes black and displays this message: stop: 0x000000D1 (0xE4434040,0x000000FF,0x0000001,0xBE9C10F0) Driver_IRQL_not_less_or_Equal and I have to manually reboot. Most commonly occurs when transfering files FROM this PC TO a network peer PC, but can happen when doing other normal tasks like running Word 2000. Then when I reboot, I always see the message: \systemroot
system32\drivers\ausbd.sys not found. I’m not sure the 2 messages are related, but would like to solve both if possible. Thank you!