Here are two ways that a hard reset Huawei Y600-U20 can be achieved.
warning: a hard reset erases all data so its advisable to have a backup first.
1 Ensure that the phone is on.
2 From the home screen open MENU then select SETTINGS.
3 Then select BACKUP&SELECT and then select FACTORY DATA RESET.
4 select RESET PHONE then tap on ERASE EVERYTHING.
In a short while the hard reset process will begin .
1 First switch off the phone by holding down the POWER OFF switch for a few seconds.
2 Now Press the Volume Up and Power buttons at the same time for about 5 seconds.
3 Release the keys when the black ‘Recovery Mode’ screen shows up.
4 Select the FACTORY RESET using the volume keys to navigate and the power button to confirm selection.
5 Select YES–DELETE ALL USER DATA using the sideways volume buttons to navigate and power button to confirm selection.
6 Select the REBOOT SYSTEM NOW to restart.
Restarting the phone begins the hard reset.