Hi, please do a uninstall and reinstall this way : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 61.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/ IMPORTANT

Please let us know if this solved your issue or if need further assistance.

Well there went an hour of my life with no results.

As I said before, I followed all instructions in the topics and nothing works. And followed your instructions to the 'T' and nothing. Still cant set FireFox to default browser.

Please give me useful help and fix this.

Did you try installing it as "Admin" install option?

Yes I did

There is a command line switch "-setDefaultBrowser" that you could try.

• https://developer.mozilla.org/en-US/Command_Line_Options

Finally, why was this so hard? Further investigation showed Microsoft pushed an update and this is when FireFox quit working. You would think Mozilla would be on top of that.

Its fully working now.

I have the same problem. I have reinstalled Firefox 62.0 on a new Win10 Home 64 bit computer. Windows does not recognise Firefox as a browser option. I looked at ttps://developer.mozilla.org/en-US/Command_Line_Options but this is a guidance note, which gives no information on how, where or when to apply the switch as the default mode for all actions on the computer. I imagine that MS is deliberately making it difficult to use Firefox. If so, they are succeeding.