AT&T’s Microsoft Lumia 640 and Verizon's Lumia 735 smartphones are now receiving the Windows 10 Mobile update over the air (OTA).
Both AT&T and Verizon are rolling out the firmware in phases, meaning Lumia 640 and Lumia 735 users may have to wait for a couple of days before it hits all the handsets.
GSM Arena says AT&T's Lumia 640 owners can manually look for the software update by navigating to Upgrade Advisor app. Verizon's Lumia 735 owners, on the other hand, can go to Settings -> Update & Security -> Phone update -> Check for updates.
Verizon’s support page says, upon updating the Lumia 735 to Windows 10 Mobile, the device should show the following software version: “02171.00002.15194.03084.”
Microsoft released a YouTube video sometime toward the beginning of 2016 on how to upgrade to Windows 10 Mobile. According to the video, Lumia handsets running the Windows Phone 8.1 version of the operating system must download and install the Upgrade Advisor app, available in Windows Store. This app will check if the Lumia device is eligible for an upgrade.
