I had done that but with the driver that I had been using, not the newest one. I had followed the instructions for deleting the old driver, and reinstalling. But since my card was older, I was concerned about trying to install a new driver that recommended updating to SP2. I'd heard from people who had a lot of problems after installing it.
I had actually tried downloading the newest driver, but couldn't find any instructions for deleting the old ones, so I just installed it. When it still didn't work, I pulled out the one I had been using which did have instructions for deinstalling and installed it. When that didn't work, I had decided to use a backup copy of my system from October, but then discovered the missing dlls.