Cleaning the Prefetch Folder Negative

Myth - “Deleting the contents of the Prefetch folder improves performance.”

Reality - Deleting the contents of the Prefetch folder will reduce application launch and windows boot time performance. Every time you delete an application’s Prefetch (.PF) file you will cripple that application’s load time the next time you go to launch it. Even though Windows XP will simply re-create that application’s Prefetch (.PF) trace file, that application’s optimal load time will not be restored until after the second time you launch that application and the system has been able to go idle and fully run the prefetch optimization. Windows XP automatically cleans the Prefetch folder down to the 32 most used Prefetch (.PF) trace files when the folder reaches 128 files so they do not needlessly consume space. This cleaning is only done when the system has gone idle. Prefetch (.PF) trace files are not a cache and are not preloaded into memory upon windows startup. They are never even accessed until you launch an application. Only one Prefetch (.PF) trace file per application is created. There is never ANY reason to delete these files. - Source - Source 2 - Source 3 - Source 4 - Source 5