This step-by-step article describes how to adjust the refresh rate of your monitor in Windows XP.
How to Change the Screen Refresh Rate of Your Monitor
Click Start, click Control Panel, click Appearance and Themes, and then click Display.
Alternatively, right-click the desktop, and then click Properties.
Click the Settings tab, and then click Advanced.
Click the Monitor tab, and then click the screen refresh rate that you want to use.
The default refresh rate setting is 60 Hertz (HZ); however, your monitor may support a higher setting. Check your manufacturer's documentation for information about the settings that your monitor supports.
If you use a higher refresh rate, you can reduce the rate that your screen flickers; however, if you specify a refresh rate that is too high for your monitor, your screen may become unusable and your hardware may be damaged.
Changes to the refresh rate affect all users that log on to the computer.