Com port problems w/Cisco router

O/S- Win2000. I have a Cisco 2501 hooked up to a serial port using the console output from the router and using hyperterminal to make connection. When I try to open the connection I get “unable to open Com1-check you port settings” I have checked and re-checked and everything seems to be OK. I have used the router on other O/S’s and worked fine. Any help would be appreciated
Thanks