Firefox Keeps Re-enabling Bing

Barman58 said:

Saw this a little late but immediately thought of a malware owned Scheduled Task due to the persistence of the issue ...

There are some options here... Slightly different method as this creates a search tab, but the concept is similar

New Bing tab at start up | Firefox Support Forum | Mozilla Support

If the issue returns, (hopefully you will never need it)

Hopefully not, so far so good at least. Normally, I can reset it to Google and the next time I open a new tab, it resets to Bing but that doesn't seem to be happening right now. It never opened up a separate tab on its own and I've run every anti-malware program under the sun and come up empty. Hopefully whatever was screwing with Firefox is gone with the old version. Thanks for the suggestion though.

Just a follow up for anyone else left with the same problem after uninstalling Lavasoft Adaware WebCompanion.

I just had a look at a file here:

C:\Program Files\Mozilla Firefox\defaults\pref

The dodgy file was named dsengine.js and if inspected with a text editor you can see that the file belongs to Lavasoft Adaware WebCompanion.

Deleting the file solves the problem.

Once you know the name of the problem file it's easy to find a thread on the subject.

After uninstalling Adware (WebCompanion), I still get my default search engine set to | Firefox Support Forum | Mozilla Support

Josey Wales said:

I use Google on Fx 57.0.4 and it never changed to Bing. I removed every other search engine. I never used Bing.

So did I. And Bing keeps coming back, even though I removed it and even though my search default is google.

Don't know if this thread has been resolved or not, but I had the same frustrating problem a long time ago as well but managed to solve after it a couple of days or so....

Firefox default for Windows 10 - Google Search