I noticed you didn't say that you did not have a modem, just that you did not use it. Check to see what com it is on if you do have one. The modem doesn't have to be actively in use, it could be any software that would answer the line (fax or answering maching software) that could be setting the modem to active and disabling that com port. Or if it is an ISA modem it will not share the IRQ regaurdless of weather it is active.