A CRC Checksum error indicates a problem reading the disc. You'll need to attempt to clean the disc or if that fails buy a new copy.
this douse this two every oblivion games ihave my disc looks like new and i have got a new one and now it is doing the same thing=.I HAVE 7 copyof the game that i have got from the store and the store will not tack the game back becouse it is open. is thers a way i can get a free download becouse iam getting sick of buying new copy every year or everytime i get a new pc