To change the display settings on a computer running Windows Vista or a newer version of the Windows operating system, access the Appearance and Personalization section in the Control Panel, and modify the resolution. If using multiple monitors, modify the settings in the Display section.
Click on the Start button, and select the Control Panel option. Make sure that the elements are displayed as categories by selecting Category from the drop-down menu next to the View By option. Click on the Adjust Screen Resolution link in the Appearance and Personalization section, and select the desired resolution. The recommended resolution is one that fits your monitor natively. Other resolutions may result in a blurry display if you’re using an LED or an LCD monitor.
To modify the display settings while using multiple monitors, select the one you wish to use as a primary display by clicking on it, and check the box next to the Make This My Main Display option. To change the display behavior, select one of the four available options from the drop-down menu next to the Multiple Displays option. If the monitors feature different native resolutions, they use the lowest common resolution as long as the display is extended or duplicated across multiple monitors.