Microsoft explains why deleting Prefetch slows down Windows 11

Microsoft confirmed that the Prefetch folder speeds up app launches and that clearing it frees little space while temporarily slowing startup. Windows 11 keeps up to 1,024 .pf files and deletes the oldest ones automatically.

• Windows 11 keeps up to 1,024 Prefetch files and prunes old ones
• On a test PC, 481 .pf files took just 13 MB of disk space
• After clearing, Clipchamp and MS Store opened noticeably slower
• Prefetch is separate from SysMain, formerly Superfetch