Jos,
I can't say for sure but it should work just fine. In my previous life I dealt with a lot of ATM machines and used a DOS based toolkit I cobbled together to diagnose problems (before I knew about PC-Doctor).
PC-Doctor is running on everything from PC's to slot machines and medical equipment. As long as it is PC based, which the Wincor/Nixdorf units are, it should work great.
-Fred