I reset my Windows 7 computer to the factory settings. After I had successfully done this, I tried to download and re-install my Norton subscription. At the end of the install I get an "Unrecoverable Error" message, indicating the install is not complete. The troubleshooting option I am given is to try again. That does not work. The next solution offered is to run the Norton Removal tool. I have done this before, and it has solved installing problems. However, when I download and try to run it, I get "Invalid signature" and the program will not run. I have tried restarting the computer and retrying the process several times and don't know how to go further. Thanks for any help.