Deleting Prefetch to speed up Windows actually made PCs slower, and a Microsoft developer explained why
AI-summarised brief · reviewed before publication
Deleting the Prefetch folder does not speed up Windows PCs and can actually slow app launches, a fact confirmed by Microsoft developer Ryan Myers and recent testing on Windows 11. Prefetch files, introduced in Windows XP, store lists of pages and files needed for an application, allowing the OS to rebuild them on first launch; clearing them forces a rebuild and introduces a temporary delay. Modern Windows versions retain up to 1,024 Prefetch entries and automatically purge the oldest, keeping the folder typically under 30 MB. Experiments on a standard Windows 11 machine and a low‑spec virtual PC showed only marginal speed differences for most apps, but noticeable lag for slower programs such as Clipchamp and the Microsoft Store after deletion. Microsoft’s incident response team reiterates that Prefetch remains enabled by default to improve launch performance, especially on traditional HDDs.
💡 Why It Matters
- · Users waste time and risk slower performance by following outdated cleanup advice that ignores Windows’ built‑in management of Prefetch files.
