Please help me, I downloaded smallville S08e1 off the internet and it says when I try open it says!!!!!!?

an error has accrued the thing will now closs and says debug or closs. I scanned it for viruses none found I when I downloaded it of the internet the comments said Works great thanks works virus free. and it has got alot of seeders so I downloaded it. and now I want to play it in windows media player it wont work it says that. PLEASE HELP ME!!!!!!!