Dragon - sorry I was away - I do not do most nights as I have kids
Ok you need to remove the current and old drivers that you have on the system - these are located in the C drive. They are stored in C:/NVIDIA
There will be some numbers 168.00 etc if there are more than 1 thats part of the cause-
you need to delete all of them and when that's done run the driver cleaner program that will clear all of the other remnants that are hidden that you cannot remove - when thats all done restart the PC and when it reboots install the newest NVIDIA driver and see whats what.
I will in the mean time see if your card requires 2 PCI 6 pin cables or just the one.