Is it actually uninstalling Firefox, not just resetting your default browser (e.g., to Internet Explorer or Edge)?

It actually uninstalls and needs a new install.

I think it related to the security software doing the uninstall. Have you disable the security software?

BTW, did this issue start after u made any major changes to your setup (i.e., hardware, OS, or change of your browser to Firefox from Internet Explorer or Edge)?

Also note, if your computer has a processor older than Pentium 4, Firefox is no longer supported as of version 49. But u can use an older version of FF. To address this issue, use this link:

[CPUs not supported by v49]

Also might help to read this article re DL of Firefox:

[to download and install Firefox on Windows]

I actually uninstalled AVG free and it still happens.

The only other programs I have are Malwarebytes free, Superantispyware free and Ccleaner. They only run manually.

It's hard for me to believe that out of millions of Firefox users I'm the only one with this problem.

"It's hard for me to believe that out of millions of Firefox users I'm the only one with this problem."

yeah, i've often thought that about my own computer woes. i'm starting to realize, tho, that there are also umpteen-zillion variations, due to everybody having specific H/W, OS versions, etc.

i wonder whether your system recorded crash reports due to these FF events? u might wanna try looking after FF gets UNinstalled, but before u REinstall:

1. Press +R on the keyboard. A Run dialog will open. 2. In the Run dialog, type %APPDATA%\Mozilla\Firefox\Crash Reports\ and press Enter.

if there are files in those folders, they might help FF folks to analyze what is happening.

NOTHING in: %APPDATA%\Mozilla\Firefox\Crash Reports\

Still Hard for me to believe that out of millions of Firefox users I'm the only one with this problem.

Come on folks........ Someone out there must have an answer for this problem.

computer reboot always uninstalls Firefox (Win 7 Pro) Every time I restart computer (Win 7 Pro) Firefox needs to be reinstalled.