Right click on any blank portion of the desktop and a menu will appear that looks like this.
Select and click Properties with the left mouse button. You will see the Display Properties dialog box. It always comes up with the Background tab selected.
Click on the Settings tab.
As you can see by reading the screen, you have a few options. Grabbing the slider bar with the mouse pointer and dragging it to the right provides higher resolutions, dragging to the left gives lower resolutions. Your monitor is running at whatever resolution is listed in the Screen area section of the Display Properties dialog box. If it’s 640 by 480, change it to at least 800 by 600 by sliding the bar.
The number of colors may be anywhere from 16 to True Color (32 bit), which gives you millions of colors.
Depending on your graphics card, you’ll be able to select one of the options. The better your card, the more colors you can display, and the higher resolution you can use. Experiment with this until you find a level that is optimal for you—attempt the highest number of colors with at least 800 by 600 resolution.
Click OK. You’ll see the dialog that says “Windows will now resize your desktop. This could take a few seconds, during which your screen could flicker.” If Windows is behaving, the statement made in the box will be accurate. The flickering screen is no problem at all.
Click OK to accept the proposed change in resolution.