My garmin is frozen how can i rest the unit - Garmin StreetPilot c550 GPS Receiver

There is a Reset button on the right side of the unit under the faceplate. At the top center of the faceplate is an indentation. Stick your fingernail under this and pull it forward. Then, gently remove the faceplate and you will see the Reset button. Press this and see if it helps. If not, there is a Master Reset technique, but doing this WILL ERASE ALL OF YOUR FAVORITES. If you have no choice, press and hold the bottom right of the screen and press the power button. The unit should reset, but again, all your favorites will be gone.

With the garmin off, hold down the right bottom of the screen and turn the garmin on, it will then ask you if you want to perform a hard reset. Choose yes and that should fix your problem.