Sure they can - Portmon is a classic example.

>I haven't workied with serial access in a while, but IIRC you won't get around that issue because serial ports can not be shared w/o dedicated hardware (serial multiplexer maybe).
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>The only thing I can think of is to have your app remove or change the port for the printer driver, open the port and check it, and hook up the printer driver again. Not sure if that can even be done - depends on the OS I think.
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