How to Determine if Your Computer is Joined to the MAIN Domain
Windows XP Professional
Press control+alt+delete on your computer. You should see a "Windows Security" window similar to the one pictured below. Look at the "Logon Information" section. If it says "You are logged on as MAIN\[your RIT username]," your computer is joined to the MAIN domain. Click "Cancel" to return to your Windows session.
Click on the Windows Start button. Right-click on "Computer" from the Start menu, then choose "Properties" from the contextual menu. This will open a new window, the heading says "View basic information about your computer." Look for a section labeled, "Computer name, domain, and workgroup settings" (see below). If the "Domain" field says "main.ad.rit.edu," your computer is connected to the MAIN domain.