Welcome to webOS. 
Unlike the older Palm devices, the Pre is NOT a device that you want to just open the back up and pop the battery out!! **IF** you want to reseat the battery (a common suggestion these days to deal with some battery issues), you need to properly shut the phone off. To do this:
1. Turn the phone on, and press/hold the power button until you see three options: Turn Off, Airplane Mode, Cancel.
2. Click on Turn Off.
3. PATIENTLY wait for the screen to completely turn off. 
Now the phone is off. When you're ready to turn it back on, just press and hold the power button again. Again, patience is key, this takes a bit.
RESTARTING/RESETING THE Pre.
1. Open the Device Info app.
2. Scroll to the bottom
3. Press Reset Options, then the green Restart button.
Post relates to: Pre p100eww (Sprint)
