F150 starting problems

I have a 1995 Ford P/U, 4x4 with automatic trans. It has sat unstarted for approximately 2 years in South Dakota weather. I recently have tried to start the vehicle with no luck. In removing the serpentine belt, all pulleys turn freely. Is it possible that the engine is seized up? If so, is there a solution to free it up?

Did you replace the gas. 2 year old gas can't be good.

Does the engine turn over or does it just click? If the engine turns over then the engine is not seized up.