hello adrianM, other affected uses with similar symptoms have reported that this may be caused by adware/malware.

please go to the firefox menu ≡ > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, don't know what purpose they serve, etc).
also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there.
finally, run a full scan of your system with different security tools like the free version of malwarebytes & adwcleaner.

Troubleshoot Firefox issues caused by malware

Thanks Philip, Have tried all these solutions and none have had an effect. Now Firefox will not open at all unless I keep moving the mouse?

thanks for reporting back. can you try if this makes a difference: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named layers.offmainthreadcomposition.enabled. double-click it and change its value to false (this will need a restart of firefox to take effect).

Have done this and it has speeded up but still have the same issue and have to move the mouse.

then i'm pretty much stumped what else we could try. users with similar issues all have reported that they could resolve it by removing some sort of malicious software: https://support.mozilla.org/en-US/questions/1019045#answer-628351 https://support.mozilla.org/en-US/questions/1018259#answer-625817

here's a bunch of more free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• Anti-Rootkit Utility - TDSSKiller
• AdwCleaner (for more info, see this alternate AdwCleaner download page)
• Hitman Pro
• ESET Online Scanner

I will try these even though I gave my system a full scan from Norton last night. I tried to start an online chat with Mozilla last night but after waiting 2 1/2 hours I gave up so if all else fails I will have to switch to Chrome. Thank you for all your advice and have a great day :)

hi again, any results with the mentioned tools so far?

Hi Philipp, Thanks for the kind e mail. After many attempts I have reloaded forefox after deleting all scripts and started in safe mode finaly I seen to have overcome this problem and all seems to be working OK and will give it a little time. Thanks again for your help :)

I also have tried this. And with or without the Add-on's I must move the mouse for a page to load. Getting sick of it. Mozilla must fix this issue.