[SOLVED]Mw2 error

Hey guys i have deleted my mw2 directory after formatting the pc and i noticed the disc had some dots on it that cant wipe off so i put my disc in clicked install and it says preparing too install and then a message pops up saying the system cannot read from the specified device. i need help it says retry or cancel when i click retry it just comes up with the same error

on your steam account go to games library right click call of duty mw2 multiplayer and singleplayer go to settings (i think) and click verify integrity of game cache and if anthing is missing it should dl it (i think).

u are likely to be "Pwned" , well i ono if u can ask for another disk