Official comment

1 64-bit Windows 7 and 64-bit Windows Server 2008 R2 support requires LNS Turbo Service Pack 7 and one of the following network interfaces: U10, U20, SmartServer, i.LON 10, i.LON 100, i.LON 600, or IP-852; use of the U10 and U20 interface requires an updated driver from Windows update; the PCC-10, PCLTA-20, and PCLTA-21 are not supported on any 64-bit versions of Windows; LonMaker Turbo Service Releases 1, 2, and 3 are supported on 64-bit Windows with LNS Turbo Service Pack 7; LonMaker Turbo SR4 is supported on 64-bit Windows without LNS Turbo SP7 (it is included); prior versions of the LonMaker tool require 32-bit Windows.
The Izot version of LonMaker called Izot Commissioning Tool does install on Server 2012 machines but as per the statement above it will not function with a PCLTA-21.