I accidentally installed Web Companion. And as many others, I got issues with it, specially the most frustrating one: it kept changing my default SE to "Bing Search Engine", I say this because there is another option on it which just says "Bing" and that gives me no issues. I put google back onto default and changed my homepage. But after reopening Firefox, it reverted back the default SE. However, it did not do so with the homepage (which remained in google). I looked for help and found that the best solution was to install a bunch of Adware Removals. Which I did... "adwcleaner" "malwarebytes", "totaluninstaller", "cccleaner"... You name it, I tried it. It seemed that one by one they removed everything, and often there were some things that the previous software had left behind and that the new one was able to delete. All seemed fine, I had to restart the computer a couple of times and even delete some files manually that I found just by lucky search. All for nothing. Every time I open Firefox, Bing is the default, no matter how many times I change it. It's still in my computer even though the anti-adware find nothing. I look on the shortcut but everything is in order. I go to "about:config" and change all the settings to google and remove all that direct to bing etc. I restart Firefox, still on bing, go to "about:config" again and weirdly all settings are as I left them, all set to google. But default in the options menu is Bing regardless of what it says on "about:config" I then go to addons, extensions etc and find that there's nothing in there. I've tried every single possible solution I could find on the internet, but it's still on my computer. I've lost all day because of a stupid mistake I made while installing other stuff and not paying enough attention. I welcome any kind of help and I wish you a good 2018. Don't make the same mistake I did.