First I downloaded the driver & installer I wanted from Nvidia's website. Then I removed all Nvidia software through Control Panel » Add or Remove Programs.
I rebooted (with Defraggler boot time defrag), deleted the user
updatususer, cleaned the registry and temp files, (ccleaner), and honored my paranoia by running a few more programs that yielded nothing – just a little over the top. No more
updatususer on my computer at all! Then I rebooted again.
Without altering code, I ran the downloaded Nvidia installer. It made me agree not to alter code, etc. I chose "accept" and went to the next step.
In Mode of Installation, I chose Advanced, not the default or standard installation!
I was given the option of what to install – I unchecked the NVIDIA UPDATE v1.8.15 box and let the others ride.
After installation completed and the required reboot, I have the little Nvidia bullet on my status bar, can open my Nvidia control panel, and WinXP knows it has a video driver that it will check for updates as long as the microsoft updater works for XP-64.
But no malware account on my computer. No unauthorized user account. No "We were just trying to help by tying up a little teeny bit of your bandwidth and it is purely secure, no hacker can find their way in, don't worry, we protect the one - or standard Nvidia algorithm generated - password for the administrator account we created without your knowledge but with your consent when you checked the agree box".
Hope this helps anyone else who was annoyed after replacing a video card and found a new user on their computer.