To join your computer to a new workgroup
In Control Panel, click System and Maintenance, and then click System.
In the System window, under Computer name, domain, and workgroup settings, click Change settings.
On the Computer Name tab of the System Properties dialog box, to the right of To use a wizard to join a domain or workgroup, click Network ID.
On the first page of the Join a Domain or Workgroup wizard, with the This computer is part of a business network option selected, click Next.
Select the My company uses a network without a domain option, and then click Next.
In the Workgroup box, type a name to describe your workgroup. Then click Next.
On the wizard’s final page, click Finish. Then in the System Properties dialog box, ...