Vista - problem uninstalling print server software

I have two printer hooked up to a Hawking HWPS12UG print server. I
tried installing the software for it, but could never get it to work
properly. Finally, after a day of trying I decided to just install them
as a network printer and this work. The hawking print server software
installs ports corresponding to the LPT1,USB1,USB2 ports on the server.
My problem is even though I am not using them, Windows Vista will not
let me uninstall the software and gives me an error that the P1(LPT1)
port is still in use, even though I was never using that port. Any
ideas on how to force the software to uninstall itself. I was able to
do it before by going into the registry and deleting all references to
the print server, but I don't really want to do that again as I don't
want to risk messing up the registry.

Z.K.