just sharing to you who have not understood, may be useful, please follow the instructions below if you want to know how hardreset T-Mobile G1 Android:
Resetting the T-Mobile Google G1 Android Phone
Resetting the Google phone deletes all data, including downloaded applications, and resets the phone back
to its initial state—the state before you turned on the phone for the first time. Important Make sure to back up important data you have on the phone before you perform a factory data reset.
T-mobile G1 Android hard reset
1. Press HOME > MENU, and then touch Settings.
2. Scroll down the screen, then touch SD card & phone storage.
3. Navigate to the Internal phone storage section, then touch Factory data reset.
4. On the Factory data reset screen, touch Reset phone. If prompted, enter your screen unlock pattern, then touch Erase everything.
Tip If your phone hangs or freezes, remove the battery, then wait for a few seconds, and then re-install it. After re-installing the battery, turn on the phone.
READ MORE - how to hard reset T-Mobile G1 Android
Resetting the T-Mobile Google G1 Android Phone
Resetting the Google phone deletes all data, including downloaded applications, and resets the phone back
to its initial state—the state before you turned on the phone for the first time. Important Make sure to back up important data you have on the phone before you perform a factory data reset.
T-mobile G1 Android hard reset
1. Press HOME > MENU, and then touch Settings.
2. Scroll down the screen, then touch SD card & phone storage.
3. Navigate to the Internal phone storage section, then touch Factory data reset.
4. On the Factory data reset screen, touch Reset phone. If prompted, enter your screen unlock pattern, then touch Erase everything.
Tip If your phone hangs or freezes, remove the battery, then wait for a few seconds, and then re-install it. After re-installing the battery, turn on the phone.
