Q: How can I restrict a user to logging on from only a specific computer?
A: The easiest way is to use the Log On To account policy in the user’s account in Active Directory (AD). Open the user’s account properties in the Microsoft Management Console (MMC) Active Directory Users and Computers snap-in. Select the Account tab and click Log On To. Then, click Logon Workstations, select The following computers, enter the name of the workstation you want to restrict the user to, and click Add.
—Randy Franklin Smith