Restrict certain user from using on certain workstation in Windows Server 2008

Hi, these are the steps on how to restrict certain user from using on certain workstation in Windows Server 2008.
Say you want to restrict user "smyeong"  from using computer called gpi-store4.

Step 1:  You need to add that specific computer into OU in which the "smyeong" belong to into active directory

Step 2: Then,scroll down to GPO and find that OU where smyeong reside. Right click and create "Create a GPO in this domain"  On this GPO editor, enable this feature as illustrated below

With above user entered, gpi-store4 won't allow user "smyeong" to log in into that computer.

Hope it helps..