Change the Way Windows Looks
There are other ways to customize your desktop.
You may have noticed from other pages with screenshots that my desktop looks different from yours:

You can also customize things like the desktop picture, theme, and even fonts used in your windows.
To access these things, you can do one of two things:
XP
Go to Start>Control Panel>Display
OR
Right-click the desktop and select Properties--->
To replace the background picture, select the Desktop tab at the top of the window.
You will see a list along the left side of the window. These are Windows-provided graphic files taht can be used for desktop backgrounds. Or you can select Browse on the right side, and look for a picture of your own that you want to display.
NOTE: If the picture you want to use is smaller than your desktop space, it may appear "jaggedy". Without getting into too much detail as to why this is, it's because the picture is smaller, and has to be stretched to fit your window.
Vista / 7
Right-click the desktop and select Personalize
To replace the background picture,click Desktop Background at the bottom of the window.
While you're here, notice the other ways that you can customize your windows, sounds, etc.
Select the picture you want to use for your background. You will also see a drop-down box at the top of the window. This allows you to search in other locations for a picture.
Be sure to click Save Changes when you are finished.
NOTE: If the picture you want to use is smaller than your desktop space, it may appear "jaggedy". Without getting into too much detail as to why this is, it's because the picture is smaller, and has to be stretched to fit your window.