Game Installers Corrupt

Hi there , i was experiencing a problem with my brandnew pc ,

All games installer in cd/dvd and games installer via download says corrupt when im installing them . I Tried changing os , reformat , also tried uninstalling antivirus , turn offing the firewall,add to exception , run as admin,run compatibility but still no luck .Some of my program also Crash especially google chrome , and it always Say " Aw Snap" so im forced to reload it. I did a memtest and the result is so bad , it gives me Pass= 0 and Errors= 4m+ , ididnt finish the memtest because 4m+errors and no pass = BAD RAM ,.Im thinkiing also about the RAM slot of motherboard if that is the problem . Any Idea ?. i remember yesterday im installing nba2k12 ,its 2 cd's , sometimes when im installing the first cd,it doesnt say corrupt , but when i insert the 2nd cd it says corrupt , and sometimes in just 1st cd it says corrupt , so in shortmean , the cd's are not corrupt . Think that sometimes that the 1st cd doesnt give me corrupt error , and sometimes it says corrupt , so in shortmean there is problem with some software / hardware of my computer