I have the same problem on
XP
Vista
Windows 7
It seems better at first system install time but....
it has nothing to do with the hardware since I've got it on brand new machines as well as older machines
it behaves as a sleep mode of the disk though I consistently switched that off where possible .... I mostly heve it with fast sata drives.. but there it is most annoying of coarse
How do I switch on the resource monitor ??? where can I get it or do you mean the tesk manager (of no use for the problem)
I know the CPu itself is idle , plenty of memory to waste , complete
idle disk (but I notice it mosly on directory access (10 to 20 files per directory)

Solving this problem, and it would be fun working on computers again
thanks