IH 444 clutch

My father in law has an IH 444 that has been sitting unused for nearly 2 years. we started it up, but the clutch won"t engage and let you shift into any gear from neutral. It was fine the last time it was used. Any ideas as to what the problem is?

With respect, the clutch is engaged, it won"t disengage. This common problem with stick shift vehicles, is due to the clutch friction disk being stuck to the flywheel. Three things will stick it, one is humidity that rusts it to the iron of the flywheel.
the second is mouse poop/pee that can corrode the two together. The third is varnished up old oil contamination from a leaky main bearing, over greasing the pilot bearing, or a trans oil leak.

Move the tractor in neutral so that it heads toward clear territory (no trees cars or buildings for a long way, options to drive for 1/4 mile is good even it it is around and around where tire tracks will be OK).
Block the clutch pedal down with a piece of wood and tape the wood in place.
With it not running, but warmed up so it starts easily, put the tractor in 3rd gear, and start it.
It will probably start moving forward. As it does, give it about 1/2 throttle, then hit the brakes to shock the clutch/flywheel junction.
This applies force to the stuck parts and will probably free the clutch. Repeated braking to almost stall will help, if it does not come loose at first. In some rare cases it is necessary to split the tractor to free the clutch, but I would say less than one in 30 need that effort. Jim

Jim I think he means that they can but it in gear and it wont move by the way I read it and if so the H-L shifter is prob not in gear, but if it is the other way jim is right on(but I just had to split a 424 as it would not come loose, worst rusted clutch I ever seen)