HTC One M9 User Manual page 234

234 Sync, backup, and reset
HTC One M9 not responding?
If HTC One M9 does not respond when you touch the screen or press the
buttons, you can still restart it.
Press and hold the POWER and VOLUME DOWN buttons for at least 12
seconds. HTC One M9 then restarts.
Resetting network settings
Reset the network settings when you're having problems connecting HTC One M9 to
your mobile data or Wi-Fi network and Bluetooth devices.
1. From the Home screen, tap
2. Tap Network settings reset.
3. Tap Reset settings.
4. Tap Reset settings.
> Settings > Backup & reset.