All modern operating systems use what are known as user accounts. To better understand this, we can liken the computer to an apartment building. Inside the building are many unique apartments. Each apartment has its own unique lock on the door, can be painted and decorated by the tenant, and generally is off limits to the other tenants. Likewise, each user account can have its own lock on the door in the form of a password, it can be uniquely decorated via individual backgrounds and settings, and the account and any files in it are generally off limits to the other user accounts. Of course, there are exceptions. Like the building manager, who has a master key to allow him access to any apartment as needed, there is a special type of user account known as an administrator that can peek into any other account. As the building manager is responsible for all things in the building such as the air conditioning and the plumbing and changing the locks, the administrator is responsible to make sure the computer and everything in it stays in top-notch shape in the form of software updates, virus scans, firewall settings, etc.
In Windows XP on a home network, there are three types of accounts; Guest, Limited User, and Administrator. We won’t get into the Guest account here because it’s outside the scope of this post. The limited user account type will let you do things like browse the Internet, check email, use most software such as instant messaging, word processing, and spreadsheets. The administrator account type has the keys to everything. You can do anything a limited user can do plus a lot more. For instance, you can install software, delete another user’s files, install printers and other hardware, set the system time, add and remove user accounts, etc. As apartments buildings normally only need one building manager, most computers will only need one administrator account. While your computer is not required to have any limited user accounts, it must have at least one administrator account.
Most of the time, each person that uses the computer gets their own account. Each account (and therefore each person) will get their own unique My Documents folder to keep their files in. Each account can have personal email accounts, browser bookmarks, backgrounds, address book, iTunes accounts, etc. These items are isolated from other limited user accounts. As an example, let’s say we have a family computer. The three users are Bob, Mary, and their son Larry. Each of the three has a limited user account and their own password. Setup this way, Bob doesn’t have to wade through Larry’s bookmarks of skateboarding websites when he wants to check his brokerage website. Mary can sync her iPod via iTunes and not have to dig through Bob’s music to change her play lists. Larry can set his background to display a picture of his girlfriend and it won’t interfere with Bob’s background picture of that luxury sports sedan he’s been wanting. As you can see, user accounts allow us to set up the computer so that it feels like home to each of us.
As a final note, some software will require that a user have administrator privileges to run properly. I highly recommend you find a replacement for this software if possible. You should always be using limited user accounts for your normal day-to-day routine, and log into your administrator account only when necessary. For an explanation of why this is important, please see my post ‘What’s an Administrator?’.