If I buy a game or DLC on one computer via Steam, can I play it on another?
I wanna buy it on my friends macbook tonight, then play it on my pc tomorrow night.
Solution 1:
If you buy something through Steam under your account, you can play it on any PC using that account (with the exception of some games that have a limited number of activations enforced by 3rd-party DRM, but this concern doesn't apply to MW2 DLC).