You can move an icon on your desktop by clicking and dragging it to another spot. It should stay wherever you drop it. If it snaps back in line with the other icons on the left side of the screen, it means that Auto Arrange is on. Auto Arrange will keep all of your icons in rows and columns starting at the upper left corner of the screen.

Auto Arrange can be turned on and off easily. Just right-click any blank area of the desktop. If you are using Windows XP, choose "Arrange Icons by". If you see a checkmark in front of Auto Arrange, it is on. If there is no check mark, it is off. You can change the status by clicking the word Auto Arrange. If there is no checkmark, clicking on the word will turn it on. If there is currently a checkmark, clicking on the word will turn it off.

It works in a similar manner in Windows Vista except that you will right-click the desktop and then click View to see the  Auto Arrange  option.

While you are in this area, check out the menu choices that you see. You can group icons by name, size, type, and date modified. You can also turn on a grid to be able to keep them wherever you like, but still have them in neat rows and columns. In Vista, you can even change the size of the icons in this area.