One of the main reasons that sharing a system between multiple users is complicated is that any change one user makes to the PC affects all the other users. For example, I once worked in an office in which two users who shared a PC constantly fought over the Windows color scheme. One user would change it and the other user would change it back. In a much worse case, a user who didn't know any better accidentally erased the contents of the My Documents folder, which contained documents for everyone in the entire department. You can get around these problems by implementing user profiles.
User profiles provide each user with a unique computing experience.
All the user has to do is enter a password, and they'll be taken into a session that's custom-tailored specifically to their preferences. As I'll explain later, the most noticeable of these custom attributes is the Windows desktop. Now, if Joe erases an icon, he'll only erase it for himself the other users won't be affected. Likewise, if Bob wants a blue desktop and Bill wants a red desktop, they can both have what they want. As you'll see throughout this series of articles, however, custom desktops are only the beginning.