Please do the following.

Click Help | Restart With Add-ons disabled. This will start Firefox in Safe Mode which means all your extensions will be disabled. This will eliminate an add-on as the cause of the problem.

Then click Help | About Firefox and click the Check For Updates button.

Thank you; I did that and the same still happens: Downloaded version 4 then a window came up that said: It is strongly recommended you apply this update for Firefox as soon as possible. So I Clicked: Next Then a window came up that said: Downloading Firefox: Connecting to the update server And this is where it gets stuck.....

Any other ideas, perhaps? Thank you.

OK, I think a clean install is called for given the circumstances, so please do the following.

Go to Download Firefox 4.0.1 and download a fresh installation file to the desktop. If necessary, download the file with IE8 and choose to save it to your desktop when you see the prompt.

Then go to Add/Remove Programs, scroll down to Mozilla Firefox and remove it, choosing to keep your bookmarks, customizations etc., (don't checkmark the box).

Then reboot and delete the folder called Mozilla Firefox at this location: C:\Program Files\Mozilla Firefox

Finally run the installation file you downloaded to the desktop earlier.

Your bookmarks, customizations etc., are maintained in a different location and will become available to you again once you complete the installation.

After you complete the installation, go to the Plugins Check page and update those where necessary.

Thank you, again. I will try it later. I must say, I'm just a little apprehensive about losing information... in Add/Remove Programs, you're talking about from the Windows Control Panel, right? (I just don't recall seeing an option to save bookmarks, etc.) Thanks for all your time. ;)

You can export your bookmarks as an HTML file as an extra safeguard if you wish by clicking the orange Firefox button, then Bookmarks | Show All Bookmarks.

Next, click Import & Backup and then Export HTML.

But don't worry, uninstalling Firefox won't delete them if you follow instructions above.

And yes, Add/Remove Programs is located in Windows Control Panel.

You are awesome, Xircal, thank you for all your help. :)

You're welcome.

Could you please click the "Solved It" button (or if that's missing, the "Helpful button) to take you post out of the loop?

Thanks.