Re: 460's or 266.58 issue?
So strange. These are just regular 460's?
Did you have the same issues with the 266.77's? I've used them on both my 480's and now 580's without needed to mod them.
Other than that I'm at a loss as far as the drivers not installing. Maybe try cleaning out your install completely with driver cleaner or sweeper. Might want to also try older drivers to see if your current ones somehow corrupted something that won't let you install any drivers.