Well, basically firefox won't start unless i open the profile manager and create and/or use a newly created profile. However, if i try to open firefox again after closing it with the same mozilla profile it just won't start. The mouse will briefly display a loading symbol but nothing happens. Google chrome and internet explorer work just fine if that helps.
Re: Firefox won't open unless i create new profile.
If you check the Windows task manager, is Firefox doing anything in the background, or just frozen?
You can use Ctrl+Shift+Esc to open the Task Manager, and check the Processes tab for firefox.exe. Sometimes Firefox will hang when shutting down, and then be prevented from restarting. Other times, it may hang starting up due to configuration issues. If you don't find firefox.exe at all, that could indicate a silent crash.
Some possibly relevant articles depending on the situation: