Win 98 will not identify mouse

A new installation of Win98 (reformatted HDD)fails to identify a mouse on Com1 or Com2. On startup, 2e8 & 3f8 show as “found”. The BIOS has onboard com1 and Com2 Serial ports enabled. The control panel/system/devices show 2 X com ports BUT no mouse. I have tried another HDD with win 95 loaded with no success. This all leads me to a motherboard fault.

I purchased an ISA serial card and configured com 1 and 2, then disabled onboard ports, but still no luck. Has anyone any suggestions with what should be a simple problem to overcome. Yes, I have tried various mice. Unfortunatly this GA- 6VA7 motherboard has no PS2 port, or USB onboard.