Run FF10 in Safe Mode:

• https://support.mozilla.org/en-US/kb/Safe%20Mode

If you are able to run it in safe mode then read these articles:

• Troubleshooting Add-ons
• Uninstalling Add-on
• Cannot uninstall an add-on

Also make sure that you have restarted your computer after installing/updating Firefox. Its always a good idea to restart the PC after any program has been installed/updated

A possible cause is security software (firewall) 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 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.
You need to scan with all programs because each program detects different malware.
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
• http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free

See also:

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

it is either my firewall or antivirus. I use comodo free firewall and avast free. I uninstalled 10, removed contents of file folder: C:Program files, turned off comodo and avast and reninstalled 10. it worked. then I turned them back on and it stopped responding to double click when trying to open from icon on desktop. it freezes computer everytime i try and i have to restart. thing is i looked in comodo and avast and firefox has full privilege. I exclude firefox in avast auto sandbox and in comodo it has full access. I dont know what it is about 10 my system doesn't agree with. 9 and every other version before runs perfect. I reinstalled 9 and it is working perfect. Im baffled and i dont want to spend forever trying to get 10 to work. should i just keep 9 and wait for another version. I dont want to change security. I like these.

i also ran superspyware cleaner and cleaned system of all spyware already