Disabling Cortana: the AllowCortana policy and what it does and does not remove
SHORT ANSWER
Setting AllowCortana to 0 under SOFTWARE\Policies\Microsoft\Windows\Windows Search disables Cortana's background hooks. On current Windows 11 builds Cortana is already far less integrated than it was, so the gain is smaller than older guides imply — this is a small, safe cleanup rather than a meaningful performance tweak.
Exactly what it changes
Read straight from the application source. If a tool will not show you this, it is asking for trust it has not earned.
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search
AllowCortana = 0
Policy disabling Cortana integration in Windows Search.
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search
BingSearchEnabled = 0
Stops the Start menu sending your local searches to Bing.
What it does
Cortana historically ran background processes hooked into Windows Search and the Start menu. On current builds much of that has already been unbundled by Microsoft.
The Bing search value is arguably the more useful half: it stops local Start menu searches being sent to the internet.
When it helps
- Removes remaining background hooks and a small amount of disk and CPU activity.
- Stops Start menu searches leaving your machine, which is a privacy gain and makes the Start menu feel faster offline.
When it hurts
- Voice features and any Cortana-dependent workflow stop working.
- Web results in the Start menu disappear — most people consider that a benefit.
- The performance effect on Windows 11 is genuinely small. Older guides overstate it.
How to undo it
Delete AllowCortana and set BingSearchEnabled back to 1.
Verdict
Safe and mildly useful, mostly for the Bing search half. Do not expect frames from it.
Related guides
Everything else we change is listed too
All 127 optimizations are published in full, with what each one does and which are free. You can apply any of them by hand using pages like this one — the tool exists to do it in one click and put it back after every Windows update.