Hi, have you had any updates lately or added any addons? What version of FF you using?

Use this link to check that your plugins are up-to-date. If any are listed as unknown or research, do not worry about them.

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. Is the problem still there?

Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

I have done the following: Uninstalled Firefox and reinstalled, started in safe mode, checked plugins are up to date. Nothing worked. Still get timed out, can't connect to server (even mozilla support) and difficulty getting into e-mail and usual websites.

Have you tried Windows Safe Mode?

Still having same problem after trying all of the suggestion given to me so far. Nothing works. Everything has been updated, including Firefox.

Did the problem start after updating to v44?

I uninstalled and reinstalled Firefox. I DO have v44 now but may have also had v44 before uninstalling and reinstalling. I did the uninstall/reinstall because of the problem (along with everything else above) and still have the same problem.

I think the problem is solved. As a last resort, we disconnected all the power to the computer and the Internet, then reconnected. The computer seems to be working now like it is supposed to. Let's hope it lasts. Thanks to everyone for all you help.

It's possible the problem was the modem, and rebooting it reset it.

That was very good work. Well Done. Please flag your last post as Solved Problem so others will know.