The OneCNC NCLink is a 32 bit application, meaning it can run in all 32 bit applications including Windows95, Windows Millennium, Windows 2000, XP, Vista, Windows 7 and others.
This means you can utilize your older PC's next to your machine to DNC to your machine. You can also network any of these operating systems to your OneCNC CAD-CAM PC which may be far more advanced and that may even be 64 bit.
To obtain this software you will need to register your details at the linked page.
When your details are received a link for the download will be sent to the email provided.