In my experience, Windows default = 60Hz. Change this as follows (may vary depending on your flavor of Windows): 1) right-click any blank desktop area 2) Select PROPERTIES 3) Open the SETTINGS tab 4) Click the ADVANCED button 5) Select the MONITOR tab 6) Use the SCREEN REFRESH RATE to select a higher rate (like 75). If you select too high, your monitor may go blank or display an error message. In that case, sit tight for 15 seconds (or press N) and it will revert back to its original state, where you can select a lower rate.