I have an HP plotter that I plan on trying to convert. the only real concern is, do the motors have enough power to pull the knife thru the material?
Mine is older and may or may not have more power. I have a knife assembly and I will be cutting down the housing to fit in place of a standard pen. This way I CAN USE IT AS BOTH A PLOTTER AND A CUTTER IF THE CUTTER WORKS OUT.
Hopefully there is a driver for your operating system, otherwise you can buy winline which will work on vista. Worst case, I can gut it and put in full cnc controls, and drive it with Mach3.
Best of luck.