Empty string — marks key as a URL protocol handler
sgnl\shell\open\command\(Default)
REG_SZ
"C:\...\Signal.exe" "%1"
signalcaptcha\(Default)
REG_SZ
URL:Signal Captcha
signalcaptcha\URL Protocol
REG_SZ
Empty string
📝 Notes
Signal Desktop installs to %LOCALAPPDATA%\Programs\signal-desktop\ (user-scope). All registry entries are in HKCU only.
All user data (encrypted message database) is stored in %APPDATA%\Signal\. The encryption key is tied to the user account.
Signal does not support multiple user accounts per OS user; the profile is bound to one phone number.
The sgnl:// URI scheme handles deep links such as sgnl://signal.me/#p/<phone> for easy contact addition.
The signalcaptcha:// URI is used during account registration to pass CAPTCHA tokens back to the app.
🗑️ Cleanup
# Uninstall entryRemove-Item-Path"HKCU:\Software\Microsoft\Windows\CurrentVersion\Uninstall\signal-desktop"-Recurse-Force-ErrorActionSilentlyContinue# URI handlersRemove-Item-Path"HKCR:\sgnl"-Recurse-Force-ErrorActionSilentlyContinueRemove-Item-Path"HKCR:\signalcaptcha"-Recurse-Force-ErrorActionSilentlyContinue