It depends if it is a electric start or a hand started engine. If it is an electric start, try recharging your battery,or testing the wiring and fuses. If its a hand started engine check your oil (In both cases)if youve got no oil in it, its seized! (oh dear!). Have a genral look @ the engine & blades, is anything caught in it??? Could be a thought.
Jim Cooper, March 2005