Hi, Please also try a [https://support.mozilla.org/en-US/kb/Managing-profiles new profile]. If it's okay, you can later [https://support.mozilla.org/en-US/kb/Recovering%20important%20data%20from%20an%20old%20profile?s=profile&r=1&e=sph&as=s copy the needed personal data] from the old profile. Firefox stores your personal data and settings in another location separate from its [http://kb.mozillazine.org/Installation_directory files/folder]. A new profile would have the default Firefox settings ('''Tools''' ('''Alt''' + '''T''') > [https://support.mozilla.org/en-US/kb/Options%20window '''Options'''], and [http://kb.mozillazine.org/About:config about:config] ), and usually would also be empty of any '''Extensions''' and themes ('''Appearance''') in Tools > Add-ons) and their settings. Also, a new profile would have no previous stored website data/settings etc., ('''Tools''' > [https://support.mozilla.org/en-US/kb/Clear%20Recent%20History '''Clear Recent History''']). [https://support.mozilla.org/en-US/kb/Profiles?s=profile&r=2&e=sph&as=s Profiles Howto] [http://kb.mozillazine.org/Profile_folder_-_Firefox Profile Folder & Files] [http://kb.mozillazine.org/About:config_entries about:config Entries] You can try to prevent the temporary storage by setting '''Override automatic cache management'' to 0 (zero) in '''Tools '''('''Alt '''+ '''T''') > '''Options '''> '''Advanced '''> '''Network'''. Please also note that some data like video streaming etc. may still be stored in the Windows temporary folder.

Thanks for the suggestions, I created a new profile which got Firefox working again, luckily i have setup sync so quickly restored my bookmarks etc, Great advice:)

You are welcome :)

You can use Clear Recent History to remove data. That is safer then using external program that may corrupt file. *Tools > Options > Privacy : History: [X] Clear history when Firefox closes > Settings *https://support.mozilla.org/kb/Clear+Recent+History Deleting the Cache folder (see about:cache) manually might have fixed your old profile. *C:\Documents and Settings\<user>\Local Settings\Application Data\Mozilla\Firefox\Profiles\<profile>\ The "Application Data" folder in XP/Win2K and the "AppData" folder in Vista/Windows 7 are hidden folders. *http://kb.mozillazine.org/Show_hidden_files_and_folders