Need help with installing fallout 3!!!!!!

so i just got fallout 3 for PC ... i already tried to download a ripped version and it didn't work out .. everytime i install it i get this message half way threw my installation .. "CRC error: The File C:\program files\bethesda Softworks\Fallout 3\Data\Fallout - Meshes.bsa doesn't match the file in setup's .cab file. The Medium from which you are running the setup maybe corrupted; contact your software vendor." i have no idea what to do here .. i'm new at pc games did i f*ck up my comp to play this certain game ... i installed dead space not to long ago and it worked perfectly ... no idea what to do .. HELP PLEASE

damn .. well i'm gonna try and get tech support here in a second to see whats going on thatx for the help

yea it's just this game ... i installed dead space with no problems .. i'm going back to wall-mart and get another disc and see what happends ... i think it might be just cause i tried to download the game prior to buying it possibly??B-NoQ

alright a few things.

1 make sure there are no fallout 3 files on your computer serch for them and delete any you find. if you downloaded it before you installed it may of put some bad files on there. so make sure there all gone.

2 make sure your cd/dvd drive is totally clean. sometimes some dust in there can cause that problem.

3 still could be the disk. remember just because it worked on your friends computer it may still be a messed up disk. some cd/dvd drivers are more sensitive to a damaged disk then others and cant read them as well. you ever have a scratched cd that works in one car and not another. happens with me all the time.