You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no

Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.

Check your homepage setting.

Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar. Type browser.startup.homepage

What is the value? Right-click and select Reset to restore its default value; about:home

Thank you so much for your quick response! I ran the first suggested scan and it found 5 ad/malware files. I segregated them and wound up with NO sound. Running the trouble-shooter for my audio resulted in the recommendation that I reinstall the driver. I did, and got the song back!

I'm sorry to be a pest, but this is a laptop I use for my work (I'm an adjunct college instructor) and I need it working.

FWIW, am running another scan now. This one is going to take awhile. In the meantime, I checked the homepage setting and it appeared to have been modified but the current setting (I assume--it was the one at the top of the list) was correct. I hit Reset anyway just for the hell of it.

First boot into Safe Mode with Networking to insure you can clean it correctly so it can't run. If you don't do this you will not get rid off it since it is already on your system.