Need help with k6 system

I have a k6 500mhz system that I just finished getting a new motheboard for. It has an AT form factor and I am having problems with the mouse. This may be a stupid question but what the hell is going on. I have a serial mouse attached to it, however everytime i turn on the comp it tells me it did not detect the mouse. Is it a software problem(maybe windows 98 was not installed properly) or is it a hardware problem that the serial port is not working. I have gone into the bios and checked that the port is enabled on the right com but that still does not solve my problem. Any suggestion will be appreciated.