> The problem started after this: I was burning a copy of
> Midnight Run onto DVD, and my system rebooted for no
> apparent reason. Ever since then, the hard drive has been
> constantly running.

Sometimes in Windows boards with a VIA chipset reboot when they need to access data larger than 1GB. Some antivirus programs have problems with large files as well, and F-Prot has problems with certain file types or data structures, and sometimes it takes up to 15 minutes for it to finish an operation on a file and halts the system for long periods of time.

Have you considered faulty RAM?

> My thoughts are that the system is thrashing heavily, so I
> set virtual memory to 0 and rebooted. This should have
> gotten rid of the corrupted paging file. I defragged my C:
> and D: drives. Now I just need to set up virtual memory
> for 512MB. This equals main memory size, which is
> recommended on systems with 512MB of memory or more.

You could also boot with BartPE and remove the file

> BTW, this has happened once before, and after a period of
> time my system went back to normal and the hard drive
> access stopped - again, for no apparent reason. I hate
> these problems that do not have obvious causes.

Weird... me too. Maybe open DrWatson and check your logs?