Can you delete the AppData\Roaming\Mozilla\Firefox folder or the AppData\Roaming\Mozilla\ folder if there aren't other Mozilla programs installed?

You may have to do this as Administrator or take ownership.

A likely cause of this issue is a problem with the profiles.ini file and the profile marked as Default=1 in this file is no longer present on the hard drive, so you may have to delete the profiles.ini file.

• Windows: %AppData%\Mozilla\Firefox\
  C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\
• Linux: ~/.mozilla/firefox/
• Mac: ~/Library/Application Support/Firefox/

You can use one of these to make Firefox create/use a new default profile:

• Delete the profiles.ini file to force Firefox to create a new default profile
• Use the Profile Manager to create a new profile
• Use "Choose Folder" when you create a new profile to select the location of a lost profile and recover this profile

• http://kb.mozillazine.org/Profile_Manager
• https://support.mozilla.org/kb/Managing+profiles
• http://kb.mozillazine.org/Profile_folder_-_Firefox

I can not access/delete this file even as administrator

Did you try to run chkdsk.exe program to make sure that there are no problems with the hard drive?

Did you try to take ownership of the folders and possible files?

Yes and yes... Can't take ownership as access is denied upon making changes... Think I have serious malware issues... Might have to format HD... Thanks for your help

BRENDOW:

Usually, I just install a registry file to add the "Take Ownership" option onto my right click menu. You can give that a try and see if you can take ownership that way and follow cor-el's instructions after.

• http://www.howtogeek.com/howto/windows-vista/add-take-ownership-to-explorer-right-click-menu-in-vista/ (Download "TakeOwnership.zip" at the bottom of the article.
  

You don't have to do this if you are uncomfortable messing with the registry. This'll just add a key into the registry that allows you to Take Ownership using the right clicking context menu. I can personally vouch for it

Do a malware check with some malware scanning programs on the Windows computer.
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: Home Page:
  http://www.microsoft.com/windows/products/winfamily/defender/default.mspx
• 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

After update to Firefox OS 33 this was installed. Norton says it is safe. What is it: \AppData\Roaming\Mozilla\Firefox\Profiles\75tbxxcd.default\gmp-gmpopenh264\1.1. Loaded and crash from Event report Windows 7 64 bit. Spybot recommends not running on Windows 7 64 bit.