I have used FF browser for more than a year and delighted with it being trouble free. I recently had the misfortune to lose some data which I have since recovered but this appears to have induced a fault in FF which I am unable to address or correct: When I click on the desktop icon to launch FF, I get the following message "Firefox is already running but is not responding. To open a new window you must first close the existing Firefox process or restart your system". I have tried rebooting, unable to find anything remotely related to Firefox running - even un-installed it and downloaded and installed a fresh version, but still the same message. Any idea's please?
The trouble is there is probably a corrupt file in the profile folder and un-installing Firefox doesn't remove the profile folder, so reinstalling Firefox it finds there is a profile folder already installed so it uses it.
So either a new profile has got to be generated, or the old one removed, in which case when Firefox is re-started it won't find the profile folder and it will ask to create a new one. In either case you will loose your extensions, these can be reinstalled but it was probably a faulty extension that was causing the problem in the first place, more importantly the bookmarks will be lost by creating a new profile, if you can't open Firefox to export them, then navigate to the profile folder and look for a file called bookmarks.html, just save it somewhere else so it can be re-imported when Firefox is running.