Warning: Incorrect registry editing can break Windows or apps.
Useful if Firefox still appears in “Open with” list or default apps.
If you’ve ever typed "file regedit ff" into a search engine, you are likely a Windows user trying to accomplish one of three things: file regedit ff
The Windows Registry is a hierarchical database that stores low-level settings for the operating system and applications like Mozilla Firefox. Mishandling it can crash your system, but when used correctly, "filing" (exporting/saving) Regedit keys is a powerful troubleshooting skill.
This guide walks you through everything you need to know about filing regedit data for Firefox, including step-by-step instructions, safety precautions, and advanced tweaks. Warning: Incorrect registry editing can break Windows or
Run in Command Prompt as admin:
dism /online /cleanup-image /restorehealth
sfc /scannow
Then reset default apps via Settings → Apps → Default Apps → Reset. If you’ve ever typed "file regedit ff" into
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MozillaMaintenance
Windows updates often reset default apps. To quickly restore Firefox as your default browser:
If you only need to file a single setting (e.g., the default profile path):