Try the following. First go to Windows Explorer go to Tools and then Folder Optons and then Check Show Hidden Files and Uncheck Hide Extensions and Hide Protected Files. Then boot into Safe Mode and log in as Administrator. Then go to Documents and Settings and go to the your log in name folder. Try deleting the cooikies in the Cookie Folder. Then got the the Local folder and delete the history, temp, and internet temp folders. The Firefox Cache is in the Application folder under Local, just click through till you get the Cache folder.