Correct monitor flicker (refresh rate)
Flicker can be a problem on CRT monitors. LCD monitors (also called flat-panel displays) don't create flicker.
A flickering CRT monitor can contribute to eyestrain and headaches. You can reduce or eliminate flicker by increasing the screen refresh rate. A refresh rate of at least 75 hertz generally produces less flicker. (Because LCD monitors don't create flicker, they don't need to be set at high refresh rates.) For more information about choosing the best refresh rate for your monitor, see Getting the best display on your monitor.
Open Screen Resolution by clicking the Start button , clicking Control Panel, and then, under Appearance and Personalization, clicking Adjust screen resolution.
Click Advanced settings.
Click the Monitor tab, and then, under Screen refresh rate, click the screen refresh rate you want. The monitor will take a moment to adjust. If you want to keep the changes, click Apply. If you don't apply the changes within 15 seconds, the refresh rate will revert back to your original setting.
If you notice flicker on a CRT monitor, you might need to change your screen resolution before changing the refresh rate. The higher the resolution, the higher your refresh rate should be—but not every screen resolution is compatible with every refresh rate. For more information, see Change your screen resolution.
Changes to the refresh rate affect all users who log on to the computer.