Error message: Access Denied. 7-zip. Setup file seemed to download but it would not open. For months, could not update. Never finished patching the update. I could let my computer run all night. Could not uninstall. Program was not in list of programs to uninstall. I have deleted all of the larger files. Just want to start with a fresh download of latest Firefox or version that will work. I have Windows 8.1 on an i5 laptop.