First right-click on the desktop and then left click on Properties
from the menu that appears.
The display properties
dialogue box will appear as shown in fig 1.1
below, click on the settings tab
at the top right of the box.
This slide bar is what you use to change the resolution, the options you have will depend on your graphics card and monitor, but the standard options are 800x600, 1024x768 and 1152x864.
Normally the default (in XP) is set to 800x600 which means the display will be 800 pixels wide and 600 pixels high.
This pull down box will contain the current colour options available, again this will depend on your grahics card and monitor, for best results select the highest option available.