Now that I think about it, I don't believe I've ever gotten RivaTuner to work the way it should. I was never once able to overclock video memory without problems. But the NVIDIA System Tools addition was able to overclock memory by a couple hundred MHz. Not a big deal, but better than nothing.
The interface for NVIDIA System Tools is abysmal--Logitech abysmal. Documentation is nonexistent, as far as I can tell. You can't really tell if it's working or not. I let it test for an optimal overclock, which is probably very conservative, but it's something. Whether or not it is being applied per the profile settings, I can't really tell.
I just learned about MSI Afterburner, which is still actively developed. I may try it some day.
To download video drivers from NVIDIA, I had to select the specific card, so I would assume the drivers are right. I suppose I could track down old drivers some how, but would they be compatible with current versions of DirectX and Windows XP service packs?