The Windows 10 Fall Creators Update (1709) is only available for the
following Windows 10 Mobile devices, and availability may vary by carrier and
market:
HP Elite x3
HP Elite x3 (Verizon)
HP Elite x3 (Telstra)
Wileyfox Pro,
Microsoft Lumia 550
Microsoft Lumia 650
Microsoft Lumia 950/950 XL
Alcatel IDOL 4S
Alcatel IDOL 4S Pro
Alcatel OneTouch Fierce XL
Softbank 503LV
VAIO Phone Biz
MouseComputer MADOSMA Q601
Trinity NuAns Neo
其他版本可透過Windows Insider Program
https://www.onmsft.com/news/list-of-supported-phones-for-windows-10-
mobile-fall-creators-update-grows-shorter