We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Help can't uninstall or reinstall firefox, it worked yesterday

  • 1 reply
  • 7 have this problem
  • 3 views
  • Last reply by cor-el

jasonb79
jasonb79
more options

Woke up and for some reason when I turned on my computer firefox wouldn't work. windows said "The application has failed because its side-by-side configuration is incorrect. So I tried to unistall and reinstall the program and it wont uninstall the program.

I am running window 7 ultimate service pack 1 64 bit operating system.

It says the same thing when I try and download a new copy of firefox, I can download the program but get the same error when I try and install the download.

Please HELP I hate Internet Explorer and that is the only thing I have to use.

Woke up and for some reason when I turned on my computer firefox wouldn't work. windows said "The application has failed because its side-by-side configuration is incorrect. So I tried to unistall and reinstall the program and it wont uninstall the program. I am running window 7 ultimate service pack 1 64 bit operating system. It says the same thing when I try and download a new copy of firefox, I can download the program but get the same error when I try and install the download. Please HELP I hate Internet Explorer and that is the only thing I have to use.

All Replies (1)

cor-el
cor-el
  • Moderator
  • Top 10 Contributor
more options

Seems to be caused by a corrupted Visual C++ installation (multiple versions can be installed side-by-side; SxS). You can try to use the sxstrace.exe tool to see if you can find which files are missing or corrupted and (re)install missing Visual C++ libraries.