If you want to connect to a network during Setup, you must have the correct hardware installed on your computer and be connected to your network.
If you will be using a network, first determine whether your computer is joining a domain or a workgroup.
If you're not sure, select Workgroup when you are prompted during Setup. (You can always join a domain later, after Windows XP Professional is installed.) Any computer user can join a workgroup—you don’t need special administrative permissions. You must provide an existing or new workgroup name, or you can use the workgroup name that Windows XP Professional suggests during Setup.
If you select Domain ask your network administrator to create a new computer account in that domain or to reset your existing account. Joining a domain requires permission from the network administrator.
Joining a domain during Setup requires a computer account to identify your computer to the domain you want to join. If you’re upgrading, Setup uses your existing computer account; or if there isn’t one, Setup prompts you to provide a new computer account. Ask your network administrator to create a computer account before you begin Setup. Or, if you have the appropriate privileges, you can create the account yourself and join the domain during Setup. To join a domain during Setup, you need to provide your domain user name and password.
Unless you're an advanced user, it's recommended you use the default settings.