port already open

I bought a system that had an hsp56 modem card and it has
given me many headaches. My most recent problem is even
though I have reconfigured my modem several times and even
bought a new modem. I am still recieving a 633 error
message- that the modem is not configured properly or the
com port is being used by another program. I have talked
with the tech support guys from the system manufacturer
and the internet service provider and we have tried
reconfiguring the modem re-installing it but to no avail.
pleas help me before I take a dump!@