Hello, thank you for your question. I understand that Firefox will not connect to the internet while other browsers can. You have already tried troubleshooting by killing the program in Task manager and reinstalling, as well as Safe Mode.

Safe Mode disabled addons, hardware acceleration and starts Firefox with most of the default configurations. I might recommend these steps specifically for the hanging:Firefox hangs or is not responding - How to fix as well as Firefox Can't Load Websites, But other Browsers Can

Please post back with the results.

Was not able to fix the problem after about 20 hours of work. Am currently installing a new hard drive and Windows 7. Thanks for trying.

Try to start Firefox with the about:blank page by creating a copy of the current Firefox desktop shortcut. Add a space and -url "about:blank" to the target field in the Properties.

I reloaded the old hard drive and added the -url "about:blank" to the end of the target. Firefox opens and does not hang, but when I enter any web site such as "google.com" Firefox tries to connect for about 10 seconds and then locks up with a "Not Responding" in Task Manager. I'm willing to try anything to get this to work, as this hard drive has a ton of old programs and bookmarks that I really need. Thanks.

You can check the connection settings.

• Tools > Options > Advanced > Network : Connection > Settings
• https://support.mozilla.org/kb/Options+window+-+Advanced+panel

If you do not need to use a proxy to connect to internet then try to select "No Proxy" if "Use the system proxy settings" or one of the others do not work properly.

See "Firefox connection settings":

• https://support.mozilla.org/kb/Firefox+cannot+load+websites+but+other+programs+can

Did you try to boot the computer in Windows Safe Mode?

Do a malware check with several malware scanning programs on the Windows computer.

• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware

Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Some problems occurs when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

Thanks everyone, but I gave up. Tried every suggestion without success. Scrapped the hard drive with Windows XP and the Firefox issue and have loaded Windows 7 to a new drive. I had saved a bookmark backup file from the XP machine and was successfully able to migrate it the new hard drive. Thanks again.

Well, what works, works.

Please flag your last post as Solved Problem so others will know.