When a Windows Server 2003 Terminal Server that is running in Application Mode has drive mapping enabled, disk drives can still be redirected when you clear the Use connection settings from user settings and Connect client drives at logon box.
Even though the RDP-Tcp connection properties in the Terminal Services Configuration tool show these check boxes, they only apply to Citrix Independent Computing Architecture (ICA) protocol sessions, NOT to Remote Desktop Protocol (RDP) sessions.
To disable client drive mapping during a RDP-TCP connection:
1. Open the Remote Desktop Connection dialog for the server.
2. Select the Local Resources tab.
3. Clear the Disk Drives box under the Local devices group.