Samsung i997 Infuse 4G hard reset
All data will be lost!
Press and hold VOLUME UP + DOWN + POWER on i997, release only POWER key, but keep pressing VOL +/- for 8 sec., in recovery menu (Vol DOWN to highlight, POWER key to select) then select Delete all user data.
Samsung i997 Android System Recovery detailed instructions
Android System Recovery is used for Google updates but the
average user will never need to perform a system recovery.
Note: If you entered this menu by mistake, use the Volume Up/Down keys to
select reboot system now, then press the Power key. Your phone will
then continue to boot up.
To enter the Android System Recovery mode, follow these steps:
1. With the phone turned off, press the Power key and
Volume Up/Down keys at the same time until the phone
switches on.
2. Once SAMSUNG appears, release the Power key while
continuing to press the Volume Up/Down keys
3. Continue to press the Volume Up/Down keys for at least 8
seconds, until Recovery mode is launched and the Android
System Recovery screen is displayed.
4. Release the Volume Up/Down keys.
5. The following options are available:
• reboot system now: this option turns on your phone.
• reinstall packages: this option allows you to apply updates to your
phone.
• delete all user data: deletes all data from the phone except
captures pictures and videos.
• delete cache data: allows you to delete all cache data such as log
files.
• format internal sd-card: allows you to reformat the internal sd
card.
6. Use the Volume Up/Down keys to scroll up or down, then
use the Power key to make a selection.
OR
AT&T Infuse 4G Factory data reset
From this menu you can reset your phone and sound settings to
the factory default settings.
1. From the Home screen, tap 
➔ Settings ➔ Privacy.
2. Tap Factory data reset, then tap Reset phone.
3. At the confirmation screen, tap Erase everything.
The phone resets to the factory default settings
automatically and when finished, displays the Home
screen.
Warning!: Performing a Factory data reset will erase all data from your phone
and internal SD card, including your Google account, system and
application data and settings, and downloaded applications. It will
not erase current system software, bundled applications, and
external SD card files such as music and photos.
OR
From the Home screen, tap Applications ➔ Settings ➔ Location and security.
Tap Clear storage to clear the storage (SD card or phone memory) of all contents and reset the credentials password.
or
Use this method to hard reset your Samsung i997 Infuse 4G 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.
Note: Hard reset for security reasons
Device administrators allows the phone to enhance its security.
The following options may be available depending on the type of account:
From the Home screen, tap Applications ➔ Settings ➔ Location and security.
Tap Select device administrators.
Maximum failed password attempts: specifies how many times a
user can enter the wrong password before the device wipes its data.
The Device Administration API also allows administrators to remotely
reset the device to factory defaults. This secures data in case the
device is lost or stolen.
Samsung i997 SAFE MODE
You can boot your phone into Safe Mode if you wish to
troubleshoot whether or not added applications are causing
problems with the device. Safe mode will only load basic system
software.
1. Make sure your phone is turned off.
2. Press and hold the power key to boot up your device.
3. After the “Rethink Possible” letters change from blue to black, continually tap the MENU 
key.
When the Home screen is displayed, Safe mode is displayed in the lower left corner of the screen.