No mouse after install of win2k & server

Hello,

I am new to IT and have had a problem with two of 20 win2k pro installs. With both installs the problem is the same.

Computer 1 HP Pavilion, Origianlly installed with win98se, reformated with a clean install of win2k pro updated with SP1

Computer 2: Custom built Server using an Abit dual processor mobo VP6. Clean install of win2k server updated with SP1.

After the installation is complete I did not have mouse support using the ps2 port. If I installed a serial mouse into the serial port and reboot I have both ps2 and serial mouse support, if I remove the serial I have no ps2 support. I am baffled and any help would be appreciated.

Mark