Hi Chris,
I have a Shopbot PRT 48" X 96" Router that I completely replaced all the electronics and software with the exception of the stepper motors.
I currently run it in Windows 7 32 bit on my HP Compaq 8710W laptop. I also used the PMDX 126 Break Out Board and plugged in a SmoothStepper right into the board. I also use Gerry's 2010 Screen Set. Everything works like a dream. Extremely satisfied.
If you would like to take a look at the video I did on this retrofit you can see it here.
Shopbot PRT Electronic and Software Retrofit - YouTube
John