Try reinstalling it...maybe it will work, otherwise all I can tell you is to download it(even though I don't support pirracy, ME is a too good game to just drop it off). I had the same problem on my old windows, and the third time I reinstalled it it worked.
i re installed it several times.. but no luck.... i also downloaded mass effect rip.but no luck..same problem..(i didn't drop ME. I finished it..after playing ME3 i jst wanna play ME again!!! ) Pls give me a solution to this problem..i just wanna play Me so badly!!!