Clear memory

From this menu you can clear the memory for Files, Messaging, Phonebook, Calendar, Tasks, Memo,
Games and apps, Exchange email, and Voicemail.
From this menu you can reset your phone and sound settings to the default settings.
1. Touch one of the applications to clear, or touch Select all to clear all the memory settings.
2. Touch Clear.
3. Enter your password in the Password field and touch Confirm.
4. At the Clear? prompt, touch Yes to confirm your action.

Reset Settings

From this menu you can reset your phone and sound settings to the default settings.
The following options are available:
• Select all: Phone, Display, and Sound settings are returned to default values.
• Sound profiles: only sound profiles are returned to default values.
• Display settings: only display settings are returned to default values.
• Phone settings: only phone settings are returned to default values.
To reset your settings:
1. From the Home screen, press MENU then touch Settings ➔ Reset settings ➔ Reset settings.
2. Highlight one of the options or highlight Select all and press MENU to place a check mark next to the
option.
3. Touch Reset, enter your password, and touch Confirm.
4. At the prompt, select Yes to confirm or No to cancel.

Master reset

1. From the Home screen, press MENU then touch Settings ➔ Reset settings ➔ Master reset.
2. Enter your password and touch Confirm.
3. At the prompt, select Yes to confirm or No to cancel.

Software Update

The Software Update feature enables you to use your phone to connect to the network and download any new
phone software directly to your phone.
1. From the Home screen, press MENU then touch Settings ➔ Software Update.
The phone updates with the latest software (if available).

or

Use this method to hard reset your Samsung T669 Gravity T 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 to your PC before full reset! Take out SIM card before full reset.

Restart your device to clear any temporary software  bugs

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.