hi r.sharples, thanks for posting with your troubleshooting information. there are a couple of problems apparent in there, among them some adware that's in your profile, so please perform all the following steps: # run a full scan of your system with different security tools like the [https://www.malwarebytes.org/ free version of malwarebytes],[https://toolslib.net/downloads/viewdownload/1-adwcleaner/ adwcleaner] & [https://www.eset.com/online-scanner/ eset online one-time scanner] to make sure that adware isn't present in other places of your system as well #[[Reset Firefox – easily fix most problems|refresh firefox]] #go to the firefox ''menu ≡ > options > privacy & security'' panel and under permissions check the setting to '''prevent accessibility services from accessing your browser''' #update your intel graphics driver through https://downloadcenter.intel.com/download/26813/Intel-Graphics-Driver-for-Windows-15-33-?product=81499 hopefully this should get your firefox back up and running ;-)