The value
HKCU\Software\Policies\Microsoft\Windows\Explorer → DisableSearchBoxSuggestions (DWORD) = 1. It's a per-user policy: the shell notices at Explorer start (restart Explorer or sign out/in), and Start/Web search integration stops injecting Bing suggestions for your account only.
Policy rituals that matter
- Restore = delete the value. Policies like this default to absent; the correct “restore” is removing the DWORD entirely, never writing 0.
- The Explorer key is user-writable because it's HKCU’s Policies branch — Windows honors it despite living outside GPO. That's intended layering, not a loophole.
- Machine twin skips: the HKLM version exists and takes precedence; a machine-managed domain environment wins over your local flip (a feature).
What this class of tweak demonstrates: the best private-facing settings are documented policy values — versioned, opinionated, and restorable by deletion. That's exactly the class the privacy preset uses.
ProofTune ProjectEngineering notes — every claim here names the bytes a real tool touches. Verify first, install second.