Here’s how you can format and factory reset your HTC One smartphone: I. Factory Resetting the HTC One: 1. Head to Menu>>Settings>>Backup & reset on your device. 2. Tap on Reset phone button. 3. A prompt will appear on your screen, simply hit the Erase all data button. 4. It’ll then erase all the data on your HTC One and factory reset it. 5 I have a problem to make phone to factory reset i download mode My kid make a password on phone and forget it Whe I click vol down and power buttons phone start i download mode only options I have on menu is system info, show barcode, reboot to bootloader, reboot to download mode, reboot, power down Warning All Data will be erased and restored to factory settings.Hard Reset (Factory Restore) Password Wipe1. Remove battery cover.2. Remove & insert battery When you see the screen showing an exclamation mark, do one of the following: In phones that have pressure-sensitive buttons such as HTC EXODUS 1 and HTC U12‍+, press and hold the VOLUME UP button. In other HTC phones, press and hold the POWER and VOLUME UP buttons. You'll then see the Recovery mode screen. Click on “Reset options” from this section it will allow us to restore network options, applications or reset the HTC One mini completely. 5- Fifth step: Click on the last option called “Erase all data (factory reset)” or simply “Factory data reset”. How to factory reset on your HTC One X ? If you need to wipe your phone's data for any reason, you can perform a factory reset from the settings menu. This feature will completely erase your personal information and data from your device and make it 100% clean. How to factory reset on your HTC One X ? If you need to wipe your phone's data for First, to answer one question simply, yes you will lose all of your data by doing a factory reset unless you back it up. If you feel a factory reset is necessary, I would use a program like Titanium Backup to backup your data. This is if you are rooted. As for the issue with your SD card, it could be a number of things. Fdw6.