In order to hard reset a doopro C1, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
doopro C1 device will be brought back to the default configuration of a brand new device.
1. Press and hold the Power button until the device turns off.
2. Now press'n'hold the Power and Volume Up buttons at the same time. Wait for the doproo logo to appear on the screen and release them.
3. Let go of the Volume Up button after the Recovery Mode starts.
4. Continue by selecting the wipe data/factory reset option. To do it, use Volume buttons to navigate and Power button to select the option.
5. Select Yes from the newly opened menu, confirm with Power button.
6. Lastly, use Power button to select reboot system now. Voila!