--- title: "EnablePrefetcher and EnableSuperfetch: registry values, defaults and gaming" description: "Prefetch records what a program loads when it starts so the next start is faster, and Superfetch preloads what you use often." url: https://frozentweaks.com/tweaks/enableprefetcher-and-enablesuperfetch author: Frost LIVE, Founder of Frozen Tweaks published: 2026-10-08 updated: 2026-10-08 category: "Clean" source: Frozen Tweaks (https://frozentweaks.com) --- # EnablePrefetcher and EnableSuperfetch: registry values, defaults and gaming **Short answer:** Prefetch records what a program loads when it starts so the next start is faster, and Superfetch preloads what you use often. EnablePrefetcher and EnableSuperfetch set to 0 switch both off in the memory manager, separately from the SysMain service. In the registry it sets EnablePrefetcher to 0 under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters, and 1 more value. ## In the app - Switch: Disable Prefetcher/Superfetch (Reg) (Clean, Pro, Advanced) - Undo: Yes. Switching it off sets a standard Windows value, which may not be exactly how you had it. - Catalog row: https://frozentweaks.com/tweaks#t-1071 ## What it does Prefetch records what a program loads when it starts so the next start is faster, and Superfetch preloads what you use often. EnablePrefetcher and EnableSuperfetch set to 0 switch both off in the memory manager, separately from the SysMain service. In the app the switch is called "Disable Prefetcher/Superfetch (Reg)", described there as: Stops prefetch traces even if SysMain is re-enabled. ## When it helps - Systems where the prefetch work itself causes disk activity at bad moments, mostly on hard disks under memory pressure. ## When it hurts - Programs and Windows itself can start more slowly, because nothing is preloaded. - On an SSD with enough memory the prefetcher costs next to nothing, so there is little to win. ## What it writes Read from the app's source. "Switching it off" is what the app writes when you turn the tweak off again. Registry values: | Key | Value | With the tweak | Switching it off | | --- | --- | --- | --- | | `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters` | `EnablePrefetcher` | `0` | 3 | | `HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters` | `EnableSuperfetch` | `0` | 3 | Source: Tweaks/prefetch_off.hpp in the app's source, app 2.0.0, checked 2026-10-08. ## The same change by hand Run in a Command Prompt opened as administrator. Make a restore point first. ```bat reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters" /v "EnablePrefetcher" /t REG_DWORD /d 0 /f reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters" /v "EnableSuperfetch" /t REG_DWORD /d 0 /f ``` Put it back: ```bat reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters" /v "EnablePrefetcher" /t REG_DWORD /d 3 /f reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters" /v "EnableSuperfetch" /t REG_DWORD /d 3 /f ``` See what it is set to now: ```bat reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters" /v "EnablePrefetcher" ``` ## How to undo it Switch the tweak off in Frozen Tweaks. It writes EnablePrefetcher back to 3, EnableSuperfetch back to 3. ## Verdict Mostly folklore on modern hardware. Leave it on unless you measured a problem. ## Questions ### What does the "Disable Prefetcher/Superfetch (Reg)" tweak change in Windows? In the registry it sets EnablePrefetcher to 0 under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters, and 1 more value. The full list is in the table on this page, read from the app's source. ### What is the standard value of EnablePrefetcher? Frozen Tweaks writes 3 when you switch the tweak off, which is the value it treats as the Windows standard. With the tweak on, EnablePrefetcher is 0. ### Is "Disable Prefetcher/Superfetch (Reg)" safe to switch on? Mostly folklore on modern hardware. Leave it on unless you measured a problem. The main cost: Programs and Windows itself can start more slowly, because nothing is preloaded. ### How do I undo it? Switch the tweak off in Frozen Tweaks. Switching it off sets a standard Windows value, which may not be exactly how you had it. ### Is "Disable Prefetcher/Superfetch (Reg)" free in Frozen Tweaks? It is part of Frozen Pro and Elite. You can also make the change by hand with the values on this page. ## Related guides - [Windows 11 Gaming Optimization: What Still Works in 2026](https://frozentweaks.com/guides/windows-11-gaming-optimization) - [What Is Safe to Delete on a Gaming PC, and What to Leave Alone](https://frozentweaks.com/guides/what-to-delete-on-a-gaming-pc) ## More tweak explainers - [Distributed Link Tracking Client (TrkWks)](https://frozentweaks.com/tweaks/disable-distributed-link-tracking) - [Scheduled drive optimization](https://frozentweaks.com/tweaks/disable-scheduled-defrag-and-trim) - [NTFS last access and 8.3 names](https://frozentweaks.com/tweaks/ntfs-last-access-and-8dot3-names) --- Written by Frost LIVE, founder of Frozen Tweaks. Canonical version: https://frozentweaks.com/tweaks/enableprefetcher-and-enablesuperfetch