Internal modem & com 3 not recognised

My ‘Conexant’ K56 internal PCI modem still works fine on Windows 98, but since I installed 2000 Professional to dual boot, the com3 port & modem are not recognised by 2000. I installed the com port manualy using I/O range 03E8-03EF,IRQ 04 as per MS web site troubleshooter, but Device Manager still gives the error code 10 “Device can’t start” (Com port 3 doesn’t appear in the list of available ports when I try to install the modem)I have obtained a new modem driver version for my (2000)unsupported modem but I think I need to get the port working first. Another device- ‘PCI Simple Communications Controler’ has the fault code 28- “The drivers for this device are not installed” could this be related? Please help…