Can't play Modern Warfare 2. Help?

Hello dayVid and welcome to TSF!
Where did you purchase this game? As in, did you buy it from a store on disc or did you purchase it from Steam?

yeah thanks. and i bought it from a store on disc

So you have the non-steam version of MW2, that's fine. But what are your system specs (CPU, graphics card, RAM etc) and try running the game as administrator by right-clicking.

mss32.dll is related to sound - do you have all the sound drivers, a sound card etc? You want to disable hardware acceleration or at least turn it down to Basic. This is really only accomplished in the newer Windows OSes by using third party software such as Creative, Audigy, SoundMAX etc.

i can't run it as administrator, the same message pops out. how do i disable hardware acceleration?