Use this method to hard reset your Samsung A777 phone: Enter *2767*3855#. Warning! All your data including contacts, messages etc. will be lost! Copy all your necessary data/Contacts/Messages etc. to SIM or make backup on your PC before full reset!

Samsung A777

Reset Settings
You can easily reset your phone to its default settings. To reset
your phone:
1. When the Idle screen displays, press the Menu soft key and
select Settings ➔ Reset Settings.
2. The following options are available. Use the Up or Down
Navigation key to scroll to and set options. Choose from
the following:
• All
• Sound Profiles Settings
• Display Settings
• Phone Settings
• Alarms
• Bluetooth
3. Press middle button w/ AT&T logo to make your selection and press the OK soft
key.
4. Enter your phone password, if prompted.
5. At the “Reset Settings?” prompt, press the Yes soft key
to reset, or the No soft key to cancel. Once your phone has
been reset to its default settings for those selected options,
it will restart itself in order to incorporate the new settings.

Memory Management
You can easily check the amount of memory being used for
storing data, such as messages, media, calendar data, or
contacts entries. You can also delete any selected information
from your phone:
1. When the Idle screen displays, press the Menu soft key and
select Settings ➔ Memory Management.
2. The following options are available. Use the Up or Down
Navigation key to scroll to and set options. Choose from
the following:
• Clear Memory
• Used Space

Clearing Memory

1. From the Memory Management sub-menu, select Clear
Memory ➔ All to select all available categories.
You can remove the check mark by pressing middle button w/ AT&T logo.
Selecting All places a checkmark adjacent to every entry
in the list.
- or -
Select a specific category.
2. Press the OK soft key.
3. Enter your password (if applicable) and press the OK soft
key. Depending on your phone’s security settings, you may
be asked to enter your password a second time.
4. At the Clear memory? confirm screen, press the Yes soft
key to continue, or the No soft key to cancel.
5. When you are finished, press END to return to Idle mode.

If you know the hard reset using buttons / keys, pls leave a comment. All comments are welcome! :)

General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing 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.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.