Attached is a screen capture of the advert. box of the above problem.

Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

Check with ALL programs below.

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back to us!

Check the connection settings.

• Tools > Options > Advanced > Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can

I'm using Windows 8. Microsoft Safety Scanner doesn't work with Win8. I've run MalWareBytes Pro and the system is clean. I finally found the problem. The new computer with Win8 came with a program called "Hot Spot Shield." I saw the advert. for Hot Spot Shield in the unwanted ad frame. I deleted the program "Hot Spot Shield" and now Firefox 23.0.1 runs correctly with no pop up adverts.

A POX on all these unwanted programs that come with the new computers!

Thanks for the help, Guys, but here is a new one for you to use.