Try restarting Windows or rebooting your computer.

this has already been done by 2 computer repair services. mozilla recommended uninstalling Nvidia Forceware access manager but I am not sure how this will affect my computer. I am reluctant to take computer back to repair shop since they didn't fix the problem before. Thanks

See this: http://www.shouldiremoveit.com/NVIDIA-ForceWare-Network-Access-Manager-8047-program.aspx

"What is NVIDIA ForceWare Network Access Manager? (from NVIDIA)

The NVIDIA® ForceWare™ Multimedia application fully integrates all multimedia functionality into a simple-to-use interface. You can record live TV, watch DVDs, burn a favorite TV show to recordable media, listen to music, and even stream content to ForceWare Multimedia clients running on other PCs. Combined with the industry’s highest quality video and immersive surround sound for TV, DVD, music, and video playback, ForceWare Multimedia delivers the ultimate digital entertainment experience on NVIDIA Personal Cinema™ solutions and NVIDIA GPUs. At the heart of the ForceWare Multimedia application is its next-generation TV capabilities. With support for playing, pausing, rewinding, and fast-forwarding live TV, ForceWare Multimedia ensures you will never have to miss your favorite show because of phone calls, door-bells, or other distractions. Experience immersive Dolby Digital 5.1, DTS, or Dolby Pro Logic II* audio and the industry’s most advanced MPEG-2 decoder for crisp, smooth video playback of your favorite DVD movie. "

Do you need those features?

Considering the problems that application is causing with recent versions of Firefox - what is more important to you? Those rarely used features? Or using Firefox without the problems that application is creating?

IMO, the features offered by NVIDIA ForceWare Network Access Manager aren't needed unless you are connecting that PC to a widescreen TV, using a high-end sound system with that PC, or sending streaming video to other PC's. Playing and burning DVD's on that PC can be done via features that are built into Windows 10; you probably don't really need that "all in one" application unless you have a "state of the art" multimedia / multiple component setup that is run from that PC.