In order to hard reset a Acer Liquid C1, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Acer Liquid C1 device will be brought back to the default configuration of a brand new device.
1. First, please turn off the phone.
2. Second, press and hold together Volume Down + Power button until the phone vibrates once.
3. When it does, quickly release Volume down and press Volume up. You will see a new menu on screen.
4. Next, use Volume buttons to select option "Recovery".
5. Now, choose from the menu the "Wipe data/factory reset" option, using Volume buttons to browse, and Menu button to confirm operation.
6. To confirm the operation, select "yes - delete all data" with Menu key.
7. Lastly, choose the "reboot system now" option.