Not to snipe the thread and you should certainly answer Aura's questions. When you installed a new graphics card did you uninstall the current one? This step causes many headaches of black screen on startups and general strange artifacting issues.
Maybe you should try and use DDU and cleanup the drivers. (make sure you dont install any other programs it may come bundled with) I havn't used this one but I used to use it when it was called something else. Plus I havn't updated my video card for awhile now so I don't have any tips on its use but I know it served me well in the past.
Turn OFF your anti virus and malware systems while you install the latest Nvidia drivers. (just download them from Nvidia)
That would be my suggestion.
Edited by YeahBleeping, 29 January 2015 - 04:37 PM.