If your Samsung Galaxy S smartphone won’t start properly because of something you loaded on it, you may want to try to boot the phone into Safe Mode so you can undo whatever was done to cause the problem.
1. Power the phone off.
2. Turn the phone back on while pressing and holding the Menu button.
3. Keep holding the Menu button until the Home screen loads. The lower-left corner should say Safe Mode.
Once you’ve removed the offending app, you’ll want to boot normally. To do so, pull the battery from the device for about one minute, then replace it. The next time you start the phone, it should no longer be in Safe Mode.