I can't unistall Norton Anti Theft

Some months ago I have bought a "new Toshiba laptop". It came with Norton Anti Theft pre-installed, I never request that product. Now I need to install my antivirus but I can't because during the installation is required to uninstall Norton Anti Theft . I have tried many procedures (safe mode, etc). but all of them were no successful. even I have follow one procedure that this community answer but it wasn't work.

I really need uninstalled as I said before I never required the product and I never register anything.

Note: I don't understand why Norton wants to obligate to use a product, because always require an account which I don't need because I don't use Norton.

It is really uncomfortable..