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

firefox blocked my anti-virus and i can't figure out how to turn it back on

more options

you have blocked avast anti-virus .it is very difficult to turn it back on because my anti-virus was turned of by you=i have picked up 4 viruses i am extreamly unhappy with you how the hell can i turn it back on do i have to get another web browser to have an anti-virus and uninstall firefox

you have blocked avast anti-virus .it is very difficult to turn it back on because my anti-virus was turned of by you=i have picked up 4 viruses i am extreamly unhappy with you how the hell can i turn it back on do i have to get another web browser to have an anti-virus and uninstall firefox

All Replies (3)

more options

hello, firefox is neither engaged in or able to turn off your antivirus program (and if it were, it would be a very bad antivirus program - if legitimate software could affect it that way, what kind of things could real malicious software do in this case?). if you have problems with your security software then please contact the support channels of its developers instead.

more options

If you want to use the Avast Online Security extension in Firefox -- which hardly does anything, the heavy lifting is done by Avast outside of Firefox -- I suggest switching from the beta version you posted with -- where unsigned extensions are blocked -- to the regular release version, Firefox 40. Here's how:

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 40.0.2 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 program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\Fx41

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\Fx41

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

Success?

Note: Some plugins may exist only in that Fx41 folder. If something essential is missing, look in these folders:

  • \Fx41\Plugins
  • \Fx41\browser\plugins
more options

As for the four viruses you mentioned, if Avast did not block them from installing, hopefully it can still remove them. But you also can supplement Avast with some of the free cleaning tools listed in our support article: Troubleshoot Firefox issues caused by malware. Different products use different matching techniques, so you may want to try several of them.