I recently sold an older computer (Pentium 75) to a guy I know. The computer has a serial port for the mouse. I didn't have an extra serial port mouse to sell him, and he just has an extra PS/2 mouse to use. So, I bought an adapter to go from PS/2 to Serial. He hooked it up tonight, and everything went together fine. Windows detects the mouse when adding new hardware, but then afterwards, it doesn't detect it. What is the problem, and what can I do to get the mouse to work?

Why not just buy a serial mouse?
Here's one for $5 -
http://www.computernyc.com/serialmouse1.html

Because I think there's some other problem here. I think the mouse works fine.

Did you try the PS/2-to-serial adapter and PS/2 mouse on another system?

I will be this weekend. I will post what I find out.