Will not load alot of websites, followed all suggestions here with no help

Question

Completed all on line troubleshooting suggestions but mozilla refuses to load alot of sites. They come up in other browsers with no problem.

Answer 1

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.
Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.
See:
*https://support.mozilla.org/kb/Server+not+found
*https://support.mozilla.org/kb/Firewalls
Do a malware check with some malware scanning programs on the Windows computer.<br />
You need to scan with all programs because each program detects different malware.<br />
Make sure that you update each program to get the latest version of their databases before doing a scan.
*http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
*http://www.superantispyware.com/ - SuperAntispyware
*http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
*http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
*http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
You can also do a check for a rootkit infection with TDSSKiller.
*http://support.kaspersky.com/viruses/solutions?qid=208280684
See also:
*"Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked