Hey Ryan,

Vista is designed to perform a lot of processing and self-maintence in the
background. For example, defrag automatically kicks in when the system is
idle; Windows Update downloads and installs updates automatically; and the
Search Indexer will index new data and optimise indexes, also when CPU is
available (ie, system is idle).

So yes: a lot of disk activity even when the machine is unattended, is
normal with Vista.

This is actually a Good Thing - it means that your PC is actually doing some
useful work even while it is standing idle; instead of sitting there doing
nothing, until you press some button. It's better use of available
resources.

The only time you should worry is if disk I/O is associated with an
application you don't recognise. In Task Manager, under the Proceses tab,
you can add columns for I/O Read, I/O Write, and I/O Other. By sorting on
the I/O colums you can check which app is doing all the disk I/O. If it is a
process like System, CSRSS, or SvcHost.exe, there's no problem, this is
normal. If it is some process you don't recognise, it may be a virus. In
that case, update your signature files and run a full virus scan
immediately.

Hope it helps,
Andrew