|It sounds like the display adapter is running a refresh rate higher than your Monitor can handle.|
If you reboot your PC into safe mode (keep pressing F8 as your machine boots up and choose Safe Mode), go to Device manager which is in Control Panel -> System and remove the Display Adaptor driver (right-click > uninstall).
Restart your machine into normal mode and it will re-detect your graphics card and you can change the refresh-rate to something that your monitor supports.
60 Hz is a good starting point, all monitors can handle that.
If you get flicker at that setting - try 65 Hz or 70 Kz but no higher.