I'll start with the short version: Open up your R4 and remove the link at J3. Job done.

What's this all about then...

I wanted to connect my R4 gameport wheel to my XP machine. But Saitek didn't support them beyond Win98, so XP drivers don't exist. In my travels I came across this driverguide page containing the curious saitek.rar, which I have attached here. Inside is not a driver, but a couple of HTML format tutorials to modify the R4. They were originally posts on the defunct Saitek forum by Ramjet, saved and uploaded by some hero in 2004.

If you own a Saitek R4 Force wheel you know it has "Powered by Microsoft Force Feedback Technology" emblazoned across it. Thrice. It turned out it was basically the Microsoft wheel inside, just with a different hardware ID, and missing a couple of buttons. To the PC, the only thing identifying this wheel as the Saitek is that soldered J3 link. Remove it, and you have a Microsoft wheel. Optionally, you could put a switch across those pads to change modes on the fly.

I've just done this with mine, and the stories are true. Plug it into a Windows XP gameport, and importantly do not manually install any drivers. Just add a new device in the joystick control panel, select "Sidewinder [autodetect]" and it will appear as a Microsoft Force Feedback Wheel, fully functional including FFB.

There is a separate tutorial in the archive for adding the missing two buttons. Just thought I would re-share it here!