Microsoft's guide to change your region in Windows 10:
To change the country or region setting. Open Region and Language by clicking the Start button , clicking Control Panel, clicking Clock, Language, and Region, and then clicking Region and Language. Click the Location tab, select your location from the list, and then click OK.
Thanks to Bong :)
Yeah it should, it's same as apple id when you buy apps they get attached to your email id.Make sure the device and store both has your account logged in