You put the CD in the ROM and click "I Agree" for the terms and type in the key code
But really if i were you i would buy Call of Duty modern warfare 2 for PC, because i have it and it's awesome!
Go to steampowered.com and download Steam. Make a free account, and and login. Once downloaded and login, click "Store" and in the top left corner, there will be a search bar. Type "Call of Duty 4" and click Search. Click "Call of Duty 4: Modern Warfare" and click scroll down the page. Click "Add to cart". On the top left corner, click "Cart". Click "Purchase for myself" and fill in the required fields. Click "Purchase", and accept the transaction. You now have Call of Duty 4 Modern Warfare for the PC at $19.99
Go to wal-mart or best buy or ect. and but it. It comes as a CD and you install it onto your computer.
But the game and install it
Steam is probably the easiest way.
No this was only a feature in modern warfare 1; there is a hack you can download to fix this though.
There are no demos for Call of Duty: Modern Warfare 3.
No.
i dont
Modern Warfare Mobilized(the DS port of Modern Warfare 1) & Modern Warfare 3.
Modern warfare 1 or 2?
i dont know try it
Get Modern Warfare 2.
Modern Warfare 2 is better. It has improved guns and better graphics. It was also better promoted than Modern Warfare 1.
yes
Download the turrent or buy the game
No, call signs were not introduced until Modern Warfare 2.