I know a lot of people that disable the System Restore feature of Windows (XP and Vista), and I just don’t get it. Whenever an update is applied to the system, a checkpoint is created of the system configuration (some registry keys, services, system dlls, etc.) and if something goes wrong with the update you can quickly rollback to a checkpoint.
This has saved me on more than one occasion from an errant Windows Update and even regular software install. Case in point, this morning I went to upgrade my copy of VMWare Workstation 6 from 6.01 to 6.0.2 and the install sat there for 30 minutes before I had to kill it. That left VMWare in a completely toasted state and wouldn’t start. Greaaaat.
After looking around my system, I saw that none of the app’s files had been removed. It just looked like one (at least) of the services that it depends on was removed from the system (just a registry entries). Whew, a system restore to a checkpoint of just an hour earlier (due to a Windows Update) fixed the problem and I’m back up and running.
I highly recommend leaving the System Restore feature turned on.