Just formatted and installed Win10, build 10161 on a laptop. This machine ran Zwift successfully under Win 8.1.
Zwift client launches to the “create an account” dialog, but closes instantly. So far have updated video drivers (actually found Win10 drivers for the Intel integrated), but no change.
Had a look at the app log. Some details:
CLR20r3 for zwiftlauncher.exe
Now suspect this is related to .NET framework.