Vista is not a quiet OS. It's logging things, etc. You also might have less than 2GB RAM?
The cure is to go back one version of the OS.
Vista Premium (what a pain)
ASUS Striker II Formula (AI Suite loaded)
OCZ 8500 SLI Compatable
8800 GTS (G92)
WD Raptor 150 GB
Brief disk accessing about every half second. This occurs with all unnecessary processes (see Black Viper's Vista suggestions) disabled, no indexing, nothing scheduled and I'm just sitting there.
What's doing it? Any suggestions?