This is a problem I've run into. If you used the "safely remove hardware" before pulling the smart card, it's possible that the hardware it removed is the entire card reader.
What you have to do is open the case, find the wires from the card reader, unplug it, and then replug it and Windows will recognize it again. This problem is not something I've seen documented somewhere, oddly enough. The "safely remove hardware" thing works great with individual USB ports and so on, but can't differentiate individual cards in the reader.
Probably the best way to do this is to pull the plug from the device (and it would be nice if it was a single plug because if it's individual plugs you have to get them back exactly right!), start the machine back up, shut down again, plug it back in, restart again. Unplug the power cord from the back of the machine while reaching into the case.
Edited by Herk, 22 January 2007 - 07:37 PM.