Where did you download Firefox from, exactly? Firefox normally updates itself, so you should not have to download anything if you've been using Firefox for a while.

As a test, could you start Firefox the following ways and see if you get a different result. First, close all Firefox windows.

(1) Blank start page

In the Windows 10 system search box (or in the Run dialog), paste the following and press Enter to execute it:

firefox.exe -url "about:blank"

Any difference?

If you need to keep your previous session windows and tabs, use the menu button > Restore Previous Session to load that now before experimenting further.

(2) Firefox's Safe Mode

In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

In case you got something unofficial, here's my suggested procedure for tracking down and cleaning up bad add-ons and other hijackers. I know it seems long, but it's really not that bad.

(1) Open the Windows Control Panel, Uninstall a Program.

After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it.

Take out as much trash as possible here. If you're not sure, feel free to post program names or a screenshot of the list.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste
  firefox.exe "about:addons"

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. All extensions are optional; the troublemaker might not be obvious from its name.

Before Firefox 57, a link sometimes would appear above at least one disabled extension to restart Firefox to make the change effective. You can complete your work on the tab and click one of the links as the last step. In Firefox 57, disabling should be immediate, but you may need to reload pages to notice any change.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in this support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

Hopefully that will flush anything on your system and in your Firefox that could be a problem.

Hi Trackengine,

Would you please take a look at this :

https://support.kaspersky.com/us/12489

Happy112 said

Hi Trackengine, Would you please take a look at this : https://support.kaspersky.com/us/12489

Thank you but I have read that article.

jscher2000 said

In case you got something unofficial, here's my suggested procedure for tracking down and cleaning up bad add-ons and other hijackers. I know it seems long, but it's really not that bad.

(1) Open the Windows Control Panel, Uninstall a Program.

After the list loads, click the "Installed on" column heading to group the infections, I mean, additions, by date. This can help in smoking out undisclosed bundle items that snuck in with some software you agreed to install. Be suspicious of everything you do not recognize/remember, as malware often uses important or innocent sounding names to discourage you from removing it.

Take out as much trash as possible here. If you're not sure, feel free to post program names or a screenshot of the list.

(2) Open Firefox's Add-ons page using either:

• Ctrl+Shift+a (Mac: Command+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons
• in the Windows "Run" dialog, type or paste
  firefox.exe "about:addons"

In the left column, click Extensions. Then, if in doubt, disable (or Remove, if possible) unrecognized and unwanted extensions. All extensions are optional; the troublemaker might not be obvious from its name.

Before Firefox 57, a link sometimes would appear above at least one disabled extension to restart Firefox to make the change effective. You can complete your work on the tab and click one of the links as the last step. In Firefox 57, disabling should be immediate, but you may need to reload pages to notice any change.

Any improvement?

(3) You can search for remaining issues with the scanning/cleaning tools listed in this support article: Troubleshoot Firefox issues caused by malware. These on-demand scanners are free and take considerable time to run. If they finish quickly and especially if they require payment, you may have a serious infection. I suggest the specialized forums listed in the article in that case.

Hopefully that will flush anything on your system and in your Firefox that could be a problem.

Thanks for this and I have followed your points but found nothing that I was concerned about however read my latest comment as I have no found the offending issue and deleted it.

Okay thank you one and all for your suggestiohs and helpful pointers.

After much searching and 'testing' various web pages it would appear that a UK based site (looking for automotive parts) I visited some months ago had left some sort of 'script' (non technical person so that descriptor may be wrong) loitering on my PC. So I have deleted the site and 'cleaned' down my PC and since doing this it seems to have removed this annoying message.

Thanks again for the help and advice given