A. XP creates a \%systemroot%\prefetch folder to store files with a .pf extension that correspond to the files the OS prefetches at system start-up. These files are in the format <filename>-<ID>.pf (e.g., frontpg.exe-2F398878.pf indicates that XP is prefetching Microsoft FrontPage at start-up).

To prevent the OS from prefetching a file, you simply delete entries from this folder (e.g., to stop XP from prefetching outlook.exe, delete the filename that starts with outlook.exe). I recommend that you clear items from this folder once a month to remove obsolete entries.