If you choose to limit the access of the user, you have very detailed control. For example, one tab on the control panel lists all applications installed on the computer. You can then choose only the applications you want that user to access. If so, you can further create a specific list of discs that the user is allowed to access. You have similar control over printers.
Individual users can also create their own private documents.
When you restart the computer, you're presented with a list of users. After you select one, you're prompted for that user's password. The computer then adjusts itself to the setting for that user. If you want that sort of security built into your operating system, you'll have to consider getting Windows 2000. Keep in mind, though, that Windows 2000 is really geared for enterprise or network settings and not a home environment.