There are many different types of VNC available for Windows. Your best bet is to look for ones that work on all O/S's and use that one. The two I can think of off the top of my head are TightVNC and RealVNC. Give those a try and see what happens.

RealVNC: http://www.realvnc.com/products/download.html
TightVNC: http://www.tightvnc.com/

Personally I preferred using UltraVNC (back when Windows was my default system), however I had issues with it a few years back when I was slowly starting to make Ubuntu my default system... It didn't like me trying to access it from Ubuntu back then. Not sure if this is still the case, but you could give that a go too.