Windows XP hangs while idle

Hi guys, my computer locks up after about 20 minutes of being idle. It doesn't lock up when you use it, only in idle.

I ran it under safe mode and it never locked up, no matter how long I left it alone, even after repeated attempts.

I ran it back up in normal mode with all services and startups disabled, and it still locked in 20 mins.

I think I narrowed the problem down to "dfrgntfs.exe" and "defrag.exe" using the task manager. Once these services start and use the CPU at 10% for a second or two the computer completely locks. I can't do anything but press the reset button. The HD light stops flickering (if I left a download program like Bittorent open) and the LAN activity dies. I am sure it is not bittorrent because the programs runs fine if the PC is not idle, plus the PC locks up when I'm not downloading also.

I found some articles on how to disable "dfrgntfs.exe" and "defrag.exe ", but isn't there anything else I could do? I like the idea of defragging while idle. Where can I verify that the files are ok, or download new versions?

Thanks for any replies!

 

UPDATE:

I have since edited the registry to disable the services, and it didn't hang when I waited 20 minutes. I consider this a quickfix... any ideas on getting a new dfrgntfs file?