I can think of two things to try, really the first would be to try the new 260.63 beta drivers. The have a new installation interface that will uninstall your old drivers and clean out any traces automatically.
Second, I would try to uninstall your old drivers in Safe Mode. If you get something that says something like, "Windows has detected new hardware, click okay to install drivers", click cancel instead, then install your updated drivers yourself.
If those suggestions don't work, then there are other steps to take.