Your Samsung Captivate may need to be rebooted if it is responding slowly or you've noticed other performance errors. You may also decide to reboot if you just want to start a fresh session on the device. Reboot the Captivate using the correct technique, as opposed to pulling its battery, to ensure that the smartphone's files remain intact during the process. Rebooting is a straightforward procedure that takes only a few minutes.
Press the "Power" key on the upper right side of the Samsung Captivate to display the lock screen.
Slide your finger across the screen to unlock the device.
Press and hold the "Power" key until the Phone Options screen displays.
Select "Power Off" to turn off the device. Wait for the phone to completely shut off.
Press and hold the "Power" key until the device begins to reboot.