pie55q

I have bought Arma 2 CO and i have shitty internet so it would take forever to download it. is there anyway i can use the serial number i was given to verify the game files i got from a friend? (fully installed it just gives me bad key at startup). Also where should i put the files? (i have put them in the bohemia ineractive foler (along with the arma battle eye folder and my arma2 free folder) Is there anyway becouse otherwise it would take FOREVER to download it.