How to adjust the video refresh rate

Step 1.Right click on the Desktop and select Display Settings.
Step 2.Click on the Advanced Display Settings link.
Step 3I.f you have more than 1 screen connected - select the screen you want to change
Step 4.Click on the Display Adapter Properties link.
Step 5.Select the Monitor tab.
Step 6.From the drop-down list, select a suitable screen refresh rate