Firefox won't open. I followed instructions in help. I closed Firefox via Task Manager, processeRestarted my comp. It still won't work. (as a test I ran Explorer to see if that would work. It does.) What can I do to get Firefox working properly?

Question

These are the help suggestions from Firefox Help that I followed:
Firefox will not start and no error message is shown
Another program may be preventing Firefox from starting. Restart your computer to end all running programs then try starting Firefox again. If Firefox still does not start or if the problem returns, the other suggestions listed below can help you fix the problem.
An extension prevented Firefox from closing properly
Sometimes your previous Firefox session did not close properly and this prevents you from restarting Firefox. Norton IPS, Norton Toolbar, and Skype 4.0 are all known to prevent Firefox from closing properly. Firefox is still running, but no windows are open.
note: TO MY KNOWLEDGE I DON'T HAVE NORTON
1. Right-click on an empty spot in the Windows task bar and select Task Manager (or press Ctrl+Shift+Esc).
Note: On newer versions of Windows (XP, Vista, 7) the combination Ctrl+Alt+Del opens Task Manager as well.
notron360sucks-taksmanager.png
2. When the Windows Task Manager opens, select the Processes tab.
TaskManagerProcesses.png
3. Select the entry for firefox.exe (press F on the keyboard to find it) and click End Process.
4. Click Yes in the "Task Manager Warning" dialog that appears.
TaskMgrWarning.PNG
5. Repeat the above steps to end any additional firefox.exe processes, if more than one entry is found, then exit the Windows Task Manager.
6. Start Firefox normally. NOTE: THIS IS WHAT DOESN'T WORK AFTER CLOSING THE PROCESS IN TASK MANAGER AND RESTARTING THE COMPUTER...THEREFORE I COULDN'T DO THE REST OF THE INSTRUCTIONS
7. At the top of the Firefox window, click on the Tools menu, and select Add-ons.
8. Select the Extensions panel.
9. (If it is listed) Select Norton IPS and click Disable.
10. (If it is listed) Select Norton Toolbar and click Disable.
11. (If it is listed) Select Skype 4.0 and click Disable.
12. Click on Restart Firefox.
ADDITIONAL NOTE: BEFORE THIS PROBLEM STARTED TODAY I WAS ON THE WEB LOOKING UP A PHONE NUMBER = THERE WAS SOME WEIRD JAVA ERROR MESSAGE SO i DIDN'T DOWNLOAD THE PAGE AND EXITED. SOMETIME LATER IS WHEN FIREFOX NO LONGER WORKED.

Answer 1

Hi mcclausky, you may need to manually remove a policy setting from the registry. You also should scan for malware that might have created this problem.
This article lists scanning and cleaning tools other Firefox users have found helpful: [[Troubleshoot Firefox issues caused by malware]].
To check your Windows registry for policy settings that might affect Firefox or other programs, I suggest consulting a Windows forum or Microsoft's forums. For example:
* http://windowssecrets.com/forums/
* [http://answers.microsoft.com/en-us/windows/forum/windows_8-system/this-operation-has-been-cancelled-due-to/9677848e-072d-4206-87f4-9da9284d6151 This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator. - Microsoft Community]
* [http://answers.microsoft.com/en-us/windows/forum/windows_xp-security/restrictions-this-operation-has-been-cancelled-due/8af1d0cd-8fbd-4223-9396-86d7497bb275 Restrictions. This operation has been cancelled due to to restrictions in effect on this computer.Please contact your system administrator. - Microsoft Community]