Here are the steps to hard reset your MPx200:
1) Turn your MPx200 off
2) Fully charge the battery with it off. To do this put the phone on a charger until it vibrates. Then remove it for a few seconds and put it back on the charger until it vibrates again. Do that repeatedly until the vibrations are really close together. Doing this will make sure your battery gets the best possible charge to give your MPx200 the best possible battery life.
3) With the phone turned off and fully charged remove it from the charger. Press and hold the power button and the blue action button simultaneously until you get a message on the screen asking if you want to perform a Master Reset. Select Yes and wait until it boots. Booting will take a little longer after a hard reset so be patient and let it boot.
Phone: Sprint Touch Pro