Do you have the Ask toolbar installed? If so, remove it. Then set up your homepage again at Options > General.

-> Tap ALT key or press F10 to show the Menu Bar

-> go to Help Menu -> select Restart with Add-ons Disabled

Firefox will close then it will open up with just basic Firefox. Now do this:

-> Update ALL your Firefox Plug-ins https://www.mozilla.com/en-US/plugincheck/

-> go to View Menu -> Toolbars -> unselect All Unwanted/Incompatible Toolbars

-> go to Tools Menu -> Clear Recent History -> Time range to clear: select "EVERYTHING" -> click Details (small arrow) button -> place Checkmarks on Cookies, Cache -> click Clear Now

-> go to Tools Menu -> Options -> General -> When Firefox starts : select "Show My Home Page" -> Type the address of the website which you want to be your HomePage e.g. http://www.google.com

-> go to Tools Menu -> Options -> Content -> place Checkmarks on:

1) Block Pop-up windows 2) Load images automatically 3) Enable JavaScript

-> go to Tools Menu -> Options -> Security -> place Checkmarks on:

1) Warn me when sites try to install add-ons 2) Block reported attack sites 3) Block reported web forgeries 4) Remember Passwords for sites

-> go to Tools Menu -> Options -> Advanced -> Network -> Offline Storage (Cache): click Clear Now button

-> Click OK on Options window

-> click the Favicon on SearchBar -> click Manage Search Engines -> select all Unwanted Search Engines and click Remove -> click OK

-> go to Tools Menu -> Add-ons -> Extensions section -> REMOVE All Unwanted/Suspicious/Incompatible Extensions (Add-ons) -> Restart Firefox

-> go to Tools Menu -> Add-ons -> Appearance section -> REMOVE All Unwanted/Suspicious/Incompatible Themes (Persona) -> Restart Firefox

You can enable your Known & Trustworthy Add-ons and Themes later. Check and tell if its working.

Hi, thanks for your reply. I don't have the Ask Toolbar installed on my computer.

Check my reply above

Perfect! Thank you very much for your help.