I've had this problem for ages, and I finally solved it with the help of: http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox#Copy_data_to_the_new_profile. This solution will reset your settings to which sites you allow or deny to set cookies, display images, open popup windows and initiate extensions installation. 1. Close Firefox 2. Start >> Run >> '''firefox.exe -p''' 3. Create Profile >> Next >> Finish >> Start Firefox 4. Close Firefox 5. Go to C:\Documents and Settings\''[Your User]''\Application Data\Mozilla\Firefox\Profiles 6. Copy the file '''permissions.sqlite''' from the new profile folder to the original profile folder 7. Start Firefox