Usual disclaimer: Use at your own risk. Backup your registry before making any changes.
In theory this should be off by default and you shouldn't need this to disable Windows Recall. In theory.
Powershell
Disable-WindowsOptionalFeature -Online -FeatureName "Recall" -Remove
Registry
This key/path may not exist.
Create or change AllowRecallEnablement (DWORD) at HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsAI
Change value to 0
Create or change DisableAIDataAnalysis (DWORD) at HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsAI
Change value to 1
Location
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsAI
.reg file
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsAI] "AllowRecallEnablement"=dword:00000000 "DisableAIDataAnalysis"=dword:00000001
You can copy and paste into the address bar in registry editor.