ECU fitting question

My car would not crank because of the engine computer. If I get a used coputer will it work? A guy told me to only a new one will work. Please help

A crank told me a guy wouldn't start so I hit him with a used computer and he gave me a car.

Car won't start. Cars need these things to run:
Cranking (turning over)
Fuel (pressure and/or injector pulse)
Spark (strong and at the right time)
Compression (good rings valves sealing opening at the right time etc)

The battery helps crank the car
the fuel pump supplies the pressure
the computer fires the injectors and the coil
the coil (s) supply the spark
the piston rings and valves seal the cylinders.

Your car won't run because the computer is bad. A used computer may work, may not. your garonteed to git a good computer if you buy a new one. Hopefully your car will crank. Sounds like this 'guy' is well.....like ....dumb