This is true, certain versions of Window 7 have different RAM ceilings.
I am using Win7 pro and cc2014 see all of my RAM - I set PS to use 26gb, which still isn't enough sometimes. I think Win7 Home will only use 16gb and win7 Pro/Enterprise/Ultimate will use up to 192gb.
edit: sorry got the numbers wrong Memory Limits for Windows and Windows Server Releases (Windows)