Vista’s “Superfetch”, a background service used to increase overall performance on starting frequently used applications and loading files, seems to get hilarious if you tend to work with large files. Did you ever encounter much hard drive activity e.g. on a system startup after burning a 4 GB DVD, converting videos, managing virtual machines or doing something similar with large files in a previous session? It might be useful or even required to stop the Superfetch service for a moment then. This will keep it from trying to superfetch any previously used file, which might be something temporarily used … on burning a DVD you probably don’t want to keep the files on your hard disc afterwards but missed to drop them.