Did you download from

http://www.mozilla.org/en-US/firefox/all/ Download Firefox Full Installer For All languages And Systems]v41

Some users have been reporting outrageous size measurements in the Windows Control Panel "Uninstall a Program" but... that's perhaps not accurate.

Could you reality check that as follows:

Open C:\Program Files (x86)\ in Windows Explorer

Right-click the Mozilla Firefox folder > Properties

That should show a size similar to 86.5 MB

If you see a gigantic measurement, I don't what would be causing that, but you can try cleaning it up as follows:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 41.0.1 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(B) Exit out of Firefox (if applicable).

(C) Rename the current program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

I'm not sure whether that updates the total in the Uninstall a Program dialog, but it should give you a more logical result when you again right-click > Properties on the folder.

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Otherwise, there's no reason to keep the old folder except research/curiosity.