Do you have the indexing services running,
Or the system restore services ?

If you have (type services.msc in a run.box to see) then set these two values to disabled or manual. It will speed up your box anyhow.

The indexing services indexes every single file of your hard drive (also the contents) so this is a heavy proccess, the system restore services keep a restore point of your system for when your box crashes somehow. This also is quit heavy on your system resources.

Just some suggestions.