help me im have trouble transfering map files to my xbox!

[offdashizel03]

ok my problem is that i got my comp an xbox connected an stuff an i transfered the map file that i wanted from my comp to my xbox an after i did that i went on my xbox an went to file explorer an it say that the map i transfer is in the halo2 map folder where it is supposed to be(i think) so after i left file explorer i went to game halo2 an played the game but when i went to go pick the modded i sent from my comp to my xbox i couldnt find it . the game halo2 was showing it wasnt there . but meanwhile when i was in file explorer it said it was in fdrie in games in halo2 in maps can some1 explain to me what i am doing wrong or y it wont let me play on the map??
thanks
MIKE