I've upgraded the railway PC to windows 8.1, 64 bit. All of the railway doftware I use runs fine under windows 8.1. Despite the "advertised" windows 8.1 start screen, I've opted to install a utilty called "StartIsBack" that gives you a windows XP/Vista/7 style start menu. Now the PC boots to desktop and stayes there.
I've found no problem with the drivers for USB locobuffer and Digitrax PR3 (There are detailed installation instructions for the latter on the Digitrax website). We also have a mk1 Locobuffer connected to the "legacy" COM1 port and it works fine.
Traincontroller 7 runs fine; Locoanalyse runs fine.