Limitation of 10 smartcard readers in Windows Server 2012 R2, Windows 8, and later
Original product version: Windows Server 2012 and later versions, Windows 8 and later versions
Original KB number: 3144446
Starting in Windows 8, the Windows platform supports a maximum of 10 smartcard readers. If more than 10 smartcard readers are available, APIs such as
SCardListReaders return a maximum of 10. All other readers are ignored.
Although the Smart Card APIs never enforce a reader limit, some parts of the system are limited to 10 smartcard readers. This sometimes causes sporadic errors when
SCard APIs are used over terminal server redirection. There are also some performance issues that occur in this situation. To resolve these issues, a limit of 10 smartcard is built into the APIs and other parts of the code. This makes it consistent with the whole smartcard stack.