Are you overclocking your system? If you are, see if you can default your mainboard BIOS settings and see if you have any problems.
Check when you install the graphics driver if you can turn off your system anti-virus. Sometimes this can cause issues.
How is your system temperature? Can you check if you have any dust issues?
Do you have a pencil eraser? If you do, unplug your graphic card and erase the gold finger on both sides. This will improve the graphics card connectivity to the PCI-E slot.