I always install DSS on this Dell running XP SP3. Dell claims it fixes USB issues. It doesn't seem to hurt to install it, even if it's not essential. But I don't know what would happen if I didn't install it.
The Microsoft update site offered me an update ~2 weeks ago for the nvidia video driver for the ancient video card in this PC. That's the first time I ever saw an nvidia driver offered by the MS site. It didn't install correctly or didn't work correctly (not sure which) so I uninstalled it and downloaded the driver directly from the nvidia site. That one did install and is working
Surprising thing is the updated driver fixed a screen flicker that developed on this system before MS offered the update. All that leads me to believe that some recent MS update messed with nvidia drivers so they offered a fix on the MS update site.