McAfee saying it's not safe to use Firefox

Hello Diane,

It may be possible that this is a software conflict issue between Firefox and your security software. To provide you with a better explanation regarding your concern, we suggest contacting the security software developer.

Regards.

Here is a starting point for you...

https://home.mcafee.com/SupportPages/search.aspx?as_sitesearch=home.mcafee.com%2fVirusInfo%2fVirusProfile.aspx&entqr=0&access=p&getfields=description&lang=us&sort=date%3aD%3aL%3ad1&type=consumer&output=xml_no_dtd&ie=UTF-8®ion=us&client=default_frontend_us&origin=us&q=firefox+not+safe&ud=1&site=us_site.AllTopicsConsumer&oe=UTF-8

Search results for "Firefox not safe" at McAfee site.

It's possible McAfee found a PUP (potentially unsafe program) that was bundled with Firefox. It isn't necessarily a real virus.

I would not use MacAfee which is the worst possible program you could install on WIndows, and pretty much ruins the OS just by its presence.  By comparison Firefox is a highly regarded browser recommended by almost all experts in forums (who see the most cases), who have never had a nice word to say about MacAfee. 

I'd uninstall MacAfee and default to built-in Defender built by the company that makes Windows and therefore knows how to protect it best.  Defender provides absolute best Windows performance and least issues caused by almost all others. 

If this is still the factory install then be aware that most tech enthusiasts would never run a factory install larded with bloatware like MacAfee and duplicate utilities that interfere with much better versions built into Windows.  They prefer to Clean Install Windows 10  which compiles the best possible install of Windows 10 that will stay that way as long as you stick with the tools and methods given.  There's also an automated Windows 10 Refresh  that reinstalls Windows while leaving out the bloatware, saving your files. 

Until then you can go over the Windows 10 Performance and Install Integrity Checklist - Microsoft Community to make sure the install is set up correctly, optimized for best performance, and any needed repairs get done. 

I hope this helps.  Feel free to ask back any questions and let us know how it goes.