For very limited voice only control, Windows 10 in the USA can control smartthings devices with on/off control
Go to
Cortana > Notebook > Connected home
Scroll down the list too Smartthings and follow the sign in details
I dont have a voice enabled Pc, WP died a painfull death a while ago ( Sore point ) and i dont use Cortana on my droid phone so i cant vouch for how good voice control works but it is there incase you need it
As is the Ms way anyone outside the USA has to change the default Cortana language to English(US) for Connected Home to work
Its a connected thing so that is why i posted here