When you establish an RDP connection from a Windows 2000 RDP (Remote Desktop Protocol) client to a Windows Server 2003 RDP server, the SCardLocateCards function cannot find the smart card when you call the SCardLocateCards function from a Windows Server 2003 RDP server if no smart card reader is registered on the Windows 2000 RDP client.
This behavior is by design in Windows Server 2003, and different from the behavior on a Windows XP RDP client.
NOTE: To register a smart card on a a Windows 2000 client, call the SCardIntroduceCardType API locally on the Windows 2000 client.
NOTE: The smart cards are registered under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Calais\SmartCards.
NOTE: See MSDN's SCardIntroduceCardType.