In our description database there are 2 solutions for performing hard reset for HTC One M9.
Choose the first method and follow the steps to perform a hard reset. If the first solution does not work, try the next method.
Please remember! Hard reset will delete any and all data your device contains; like pictures, contacts, messages, apps etc. Everything. HTC One M9 device will be brought back to the same configuration as that of a brand new device.
1. Welcome. Start by turning your phone on (hold down the Power button).
2. Now open Menu, Settings, Backup and Reset and select Erase all data.
3. Confirm by tapping OK. Good job! Your phone is now resetting and rebooting, completing the hard reset process.
1. Lets get started. Begin by pressing the Power button to turn your phone on.
2. Now press and hold the Power and Volume Down buttons for five seconds.
3. Select Reboot to Bootloader.
4. Now select Boot to Recovery Mode.
5. Select the wipe data/factory reset option. Use Volume buttons to scroll and Power button to select.
6. Now, select Yes -- delete all user data to confirm the operation.
7. Finally, select Reboot System Now. Done, the hard reset is complete.