Ever since I upgraded to Windows Vista x64 I have been unable to use tsadmin to manage terminal server sessions on my servers. Well today I decided to attempt to figure out what was going on. Now apparently there are other issues noted by Microsoft in KB article 930056, but this didn't solve my problem. Here's what did though..
Open up your registry editor and navigate to
HKCU\Software\Microsoft\Windows NT\CurrentVersion\Terminal Server\TSADMIN
and delete the "Placement" value
Close out of Regedit
Reopen tsadmin and you should be all set.
