NAV 2016: Windows client is available in a 32-bit version and 64-bit version

https://msdn.microsoft.com/en-us/library/dd301054(v=nav.90).aspx

Однако:

The Microsoft Dynamics NAV Windows client is available in a 32-bit version and 64-bit version. On a 32-bit Windows operating system, the 32-bit version is run. On a 64-bit Windows operating system, the 64-bit version is run by default; however, you can also run the 32-bit version if it is required.