Microsoft says devices running Windows Phone 7.5 and 8.0 have reached end-of-life status and will no longer be supported.
Beginning February 20, Microsoft will turn off push notification services for Windows Phone 7.5 and Windows Phone 8.0. This means devices running those platforms will no longer receive notifications, will not receive live tile updates, and will not be able to use Find My Phone to locate the device.
Microsoft says Windows Phone 8.1 and Windows 10 Mobile remain fully supported for the time being. Devices running Windows Phone 7.5 and Windows Phone 8.0 were originally sold in the 2011 and 2012 timeframe.