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Mozilla Firefox

Version tested: 123.0 Installer type: .exe official full installer from mozilla.org

📦 Package Managers

Manager Install Command
winget winget install Mozilla.Firefox
Chocolatey choco install firefox
Scoop scoop install firefox

📁 Registry Paths

  • HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox
  • HKEY_LOCAL_MACHINE\SOFTWARE\Mozilla\Mozilla Firefox\<version> (x64 en-US)\Main
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Mozilla Firefox <version> (x64 en-US)
  • HKEY_CURRENT_USER\Software\Mozilla\Mozilla Firefox (created at first launch)
  • HKEY_CLASSES_ROOT\FirefoxHTML-<hash> (HTML file handler ProgID)
  • HKEY_CLASSES_ROOT\FirefoxURL-<hash> (http/https URL handler ProgID)

🔑 Keys

Application root (HKLM\SOFTWARE\Mozilla\Mozilla Firefox)

Key Name Type Description
CurrentVersion REG_SZ Installed version string (e.g., 123.0 (x64 en-US))

Version/Main subkey (HKLM\SOFTWARE\Mozilla\Mozilla Firefox\<version>\Main)

Key Name Type Description
Install Directory REG_SZ Root installation path (e.g., C:\Program Files\Mozilla Firefox)
PathToExe REG_SZ Full path to firefox.exe

Uninstall entry (HKLM\...\Uninstall\Mozilla Firefox <version> (x64 en-US))

Key Name Type Description
DisplayName REG_SZ Mozilla Firefox 123.0 (x64 en-US)
DisplayVersion REG_SZ Installed version (e.g., 123.0)
DisplayIcon REG_SZ Path to firefox.exe
InstallLocation REG_SZ Root installation directory
Publisher REG_SZ Mozilla
UninstallString REG_SZ Path to the uninstaller with /S for silent mode
URLInfoAbout REG_SZ https://www.mozilla.org

📝 Notes

  • All user data (bookmarks, history, extensions, preferences) is stored in the Firefox profile at %APPDATA%\Mozilla\Firefox\Profiles\, not the registry.
  • The version-specific subkey path changes with every update (e.g., 123.0 (x64 en-US) → 124.0 (x64 en-US)); query CurrentVersion to find the active path.
  • Enterprise policy settings can be pushed via HKLM\SOFTWARE\Policies\Mozilla\Firefox — see Firefox Enterprise Policies.
  • The 32-bit installer on 64-bit Windows places keys under HKLM\SOFTWARE\WOW6432Node\Mozilla.
  • The MSI enterprise installer uses the same registry structure but allows per-machine deployment via Group Policy.
  • The FirefoxHTML-<hash> and FirefoxURL-<hash> ProgIDs are unique per installation (hash is derived from the install path) to support multiple Firefox installs side-by-side.

🌐 HKCR — URL & File Handlers

HTML file handler (HKCR\FirefoxHTML-<hash>)

Key Path Type Description
(Default) REG_SZ Firefox HTML Document
shell\open\command\(Default) REG_SZ "C:\...\firefox.exe" -osint -url "%1"

URL protocol handler (HKCR\FirefoxURL-<hash>)

Key Path Type Description
(Default) REG_SZ Firefox URL
URL Protocol REG_SZ Empty string — marks key as a URL protocol handler
shell\open\command\(Default) REG_SZ "C:\...\firefox.exe" -osint -url "%1"

To find the exact hash on a given machine:

Get-ChildItem "HKCR:\" | Where-Object { $_.Name -match "FirefoxHTML|FirefoxURL" }

🗑️ Cleanup

Remove-Item -Path "HKCU:\Software\Mozilla\Firefox"           -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item -Path "HKLM:\SOFTWARE\Mozilla\Mozilla Firefox"   -Recurse -Force -ErrorAction SilentlyContinue
Remove-Item -Path "HKLM:\SOFTWARE\WOW6432Node\Mozilla"       -Recurse -Force -ErrorAction SilentlyContinue