Software Update to try updating to i OS 10.3 via OTA (over the air).
The 5, 5C, and i Pad 4 are the last i Devices to use the A6 system-on-chip and the last built with a 32-bit architecture.
To summarize, there are two big issues with i OS 10.3 and 10.3.2/10.3.1 update.
i OS 10.3 and 10.3.1 are available for i Phone 5 or newer, i Pad 4 or newer, though Apple seemingly ends support for 32-bit devices like i Phone 5 with i OS 10.3.2.
Apple is likely focusing on i OS 11 for major new features which we expect to see introduced at WWDC 2017 on June 5 next month.Be aware that it might take upwards of 24 hours to actually get the i OS 10 update delivered to your i Phone, i Pad, or i Pod. One rule of thumb: backup your device before updating.It's not uncommon for phones to freeze up during the update.Instead of doing this manually or you worry about incorrect operations can lead to malfunction, I recommend you to use a free i Phone reboot tool - Rei Boot.By getting in and then getting out of recovery mode will force an i OS device to restart.