hard drive getting hammered logon

Geez, what in the heck is going on right after logon that is HAMMERING the hard drive for, literally, 2-4 minutes? I have a realllly good computer Dell XPS 600 nforce4 chipset 3.2Ghz Pent D Dual Core 80GIG 10K SATA hard drive 2GIG RAM Nvidia GTX7800. I mean, I really wouldn't expect anything to hammer it that bad? I did notice DWM.EXE in the process tab while it was going on... any clues? Is this a bug/flaw/by design? Hopefully this will be fixed... Thanks - Billy