Invalid CD Key

[Kitharodos]

Hi.
I purchased Operation Arrowhead some months ago on my old PC. Now im on a new one with Win7 (XP on old) and tried to restore my game, put the CD key and said invalid. I backuped then from my old Hard Disk to the new one and tried to restore it again but invalid message was still there. How will I play my purchased game on my new pc?

[Dwarden]

as seen in the sticky
http://forums.steampowered.com/forums/showthread.php?t=662748

just Run STEAM as administrator

[Kitharodos]

Invalid again

[Dwarden]

Invalid again

revalidate the game file cache, if that fails i suggest You contact STEAM support

btw. what key you putting where?
the STEAM should get it automatically you dont need type anything anywhere for OA

[Kitharodos]

STEAM should get it automatically you dont need type anything anywhere for OA

strange thing is that STEAM should download and install it automatically on library but I dont see anywhere my game. I have only 1 account on steam and this is it and Im not logged in the same time from anywhere else. Why I cant see my game on library?