i was looking at amazon and MW3 pc is cheaper there then on steam. so was wandering if that version would work?

no, OF COURSE NOT.

 

[/sarcasm]

 

all MW3 require steam authentication...

Yes mate, you need to own a legit copy of MW3 in order to play IW5M, NOT

or just open the game and follow the instructions.....

Need legit MW3.

Yes, you can buy it from Amazon. All MW3 copies are installed/run through Steam either way.

Of course you do NOOOPE

Officially yes.

Yes mate, you need to own a legit copy of MW3 in order to play IW5M, NOT

*facepalm* ur wron dude, u dont need a legit copy.....

Yes mate, you need to own a legit copy of MW3 in order to play IW5M, NOT

*facepalm* ur wron dude, u dont need a legit copy.....

 

Well, if you'd read closely here: viewtopic.php?f=30&t=6810

 

It says: Steam check and Steam auth. Also try to read Mq7riX's post again. Carefully, especially the end.

Yes mate, you need to own a legit copy of MW3 in order to play IW5M, NOT

*facepalm* ur wron dude, u dont need a legit copy.....

Check my post again