HTC One M8 hard resetPerforming a factory reset using hardware buttons
If you can’t turn HTC One on or access settings, you can perform a factory reset by using the hardware buttons on HTC One.
The Fast boot option in Settings > Power must not be selected.
1. Press and hold the VOLUME DOWN button, and then press and hold the POWER button.
2. Wait for the screen with the three Android images to appear, and then release the POWER and VOLUME DOWN buttons.
3. Press VOLUME DOWN to select FACTORY RESET, and then press the POWER button.
OR if you can access to your phone
Performing a factory reset from settings
1. Go to Settings, and then tap Backup & reset.
2. Tap Reset phone.
3. If you want to delete media, documents, and other data from the phone storage, select Erase all data.
To also delete media and other data from your storage card, select Erase SD card.
4. Tap OK.
Resetting HTC One M8 (Hard reset)
If HTC One has a persistent problem that cannot be solved, you can perform a factory reset (also called a hard reset or master reset). A factory reset reverts the phone back to its initial state — the state before you turned on the phone for the first time.
The following will be removed from the phone when you do a factory reset:
- Your Google Account
- All accounts you've added in Settings > Accounts & sync and the data associated with these accounts
- Personal data that you've created or synced to the phone such as your profile, contacts, messages, email, calendar events, and more
- System and application data and settings
- Downloaded apps
Files such as your music, photos, videos, and documents can also be deleted from the storage, if you chose to do so.
Be sure to back up any data and files you want to keep before you do a factory reset.
A factory reset may not permanently erase all data from your phone, including personal information.
HTC One M8 Soft resetRestarting HTC One M8 (Soft reset)
If HTC One is running slower than normal, is unresponsive, or has an app that is not
performing properly, try rebooting and see if that helps solve the problem.
1. If the display is off, press the POWER button to turn it back on. If you've set up a lock screen, you need to unlock it.
2. Press and hold the POWER button, and then tap Restart.
3. When asked to confirm, tap Restart.
If HTC One does not respond when you touch the screen or press the buttons, you can still restart it.
Press and hold the POWER and VOLUME UP buttons for at least 10 seconds.
HTC One then restarts.
Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.!