I was given a Microsoft Sidewinder Force Feedback Pro, I thought "Cool!" until I got to checking and found that the feedback doesn't work with XP, and the stick apparently won't work at all with a USB gameport adaptor.

I did find that if it was the Sidewinder Force Feedback 2, which is USB but has smaller/weaker motors and fewer buttons, the version 4.0 software can be found at Driverguide and beaten into submission to have feedback on XP. (Same for the USB Sidewinder FF wheel.)
Another place I found that the 4.0 drivers can be forced onto 98/98SE and possibly Me for gameport Sidewinders by first installing 3.0x then 4.0 and killing the 4.0 installer when it can't find any USB devices, then using the manual device install in Windows.
The 3.0x installer checks the Registry, sees that XP is not 9x, and quits.
Makes me wonder if some frankenstein hybrid of the version 3.0x and 4.0 Sidewinder software can be hacked together to fully support gameport Sidewinder controls with force feedback in XP?
I have a Soundblaster Live 5.1 I could install for its gameport, seen several places that XP _should_ work with both one of those and onboard audio. (My onboard has some crazy number of output channels, like 7 or 8, only using a single pair of speakers currently.)
An alternate project would be something like Gremlin's USB adaptor for the original Sidewinder 3D Pro (NOT the FF!) joystick, but programmed to fool XP into treating it as a Sidewinder FF 2 so the 4.0 drivers can be used. See descentbb.net/viewtopic.php?t=7090