I used this module several years ago with a Windows 98SE System with perfect results. .......... I have tried EVERYTHING I know to get the CM11A to recognize a COM port.
I think everyone has tried to force an old piece of hardware or software to work... at one time or another. I have an old CM11A in my "big plastic X10 parts bin", myself. I also have an old win98 laptop...
I think could make it work. Finding an old working win98 PC could be a solution for you too....
for as long as the win98 machine continues to function.
But to be honest I wasn't ever all that happy with the CM11A. Because it doesn't do RF... it seemed more like a programmable timer to me.. than anything else. Of course... even the CM15A has somewhat limited RF reception.. and I felt compelled to modify my antenna right away. And I now depend on the CM15A so much... I have a backup unit... (also in "big plastic X10 parts bin").
I have learned to love my CM15A and the great Home Automation it allows me to have. But we all know (deep inside) sooner or later... it will also go the way of adding machines, black and white TV, 4:3 screen size, VCR's, my hairline AND the CM11A.