Call Of Duty / Sims

[ShortCircut]

Firsty sorry if i'm asking something that has already been asked, not that great at with all these computer forums and the 'tech speak'

The first thing is I bought Call of duty - the first one at a car boot and tried to install it on my PC and its saying i need a second disc to install, i dont have one as it only came with the one, is there anything i can do short of going out and buying the game again just for that disc?

Also i bought the sims off amazon and its a mutil pack with the first few games and expan kits in, what i didnt know is that it makes you install everything at once and my computer - desk top and my laptop just laughs at it, wont have it, is there anywhere to just get the first game online to try it before i go buying the games again for nothing? Can you download computer games online at any good site or is that not allowed?
thank you for reading this :-)