Server 2003 running disks all day long

My Server 2003 gets into a mode where the hard drives run continuously even
when there's no load on the server. The problem is so severe that the machine
stops responding and needs to be rebooted. The problem started after Desktop
Search got installed serveral years ago. I've done my best to uninstall
Desktop Search, and it seems to be gone, but I still have the problem.

When the problem is occurring, there are a number of processes that have
high I/O numbers in task manager, including svchost (PID948), csrss, lsass,
inetpub and cisvc.

Any ideas on how to fix this problem? Any help appreciated.