that x-httpd-php is a method for downloading/installing.

I would recommend scanning for malware if the site does not expect this to happen. 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:

• 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

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one. Windows 8 has antivirus built-in already.

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

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

I do have Win 8.1 and also have McAfee. I ran a full scan when this first started to happen and nothing was detected. I also did a restore to a date prior to when the message started appearing but still having the issue. All Win updates are up to date. I also used IE browser and the message is showing on that one too. I will try the Microsoft Scanner and see if it comes up with anything that McAfee did not catch. I also contacted Microsoft but so far anything they've suggested has not resolved the issue. Very odd that this just started happening on Monday. No new software was installed and everything was running fine. thank you for helping. Very much appreciated.

I ran a couple of the scans posted above and still nothing showed up to resolve the problem. Still getting the pop-up message.