One of the most frustrating errors on Windows using smart cards is:
What does this mean? It turns out there are various causes. In the specific example above the main clue is “Unknown Card”. This means that the system cannot associate a card with a minidriver that can inteface with the card. This may be because the minidriver is not installed, or because the minidriver is installed but there are problems with the registry.
It is also possible that the system does recognize the card, but the card does not meet the requirements. If that is the case, the dialog will look a little different:
In this case, the card is recognized as can be seen by the fact that the smart card is named “Taglio C2 JCOP31 (90). It is still possible that the system cannot find the appropriate minidriver due to a problem with PnP or the registry.
However it is more likely that the system is looking for a different card. This depends on the “current operation”. Perhaps the system is looking for the card that belongs to a specific certifciate, or because you have requested a certificate with 2048 bits, and the card only support 1024. There may be any number of practical reasons why the system is looking for another card and it doesnt mean the card is not working.