Can not detect Serial Mouse msg.

Windows 95, during startup, no longer sees my logitech serial mouse. My attempts to improve this have no luck so far. I tried another good mouse to the 9pin connector with same results. I tried improving the connection tightness on the pc back paneland on the motherboard where the ribbon cable connects. I tried the alternate serial connection on the mother board after that. Is there something to reset or check I missed in the software? I loaded the mouse driver, either as logitech or standarddefault, and even removed and added the mouse to the system. Still does not detect it for some unknown reason? Help.