Alternator belt squeek

I just replaced the alternator, and it started sqeeking i knew it was the belt so i went and got a new one. I put the new belt on and it stoped sqeeking for about 3 min then it started squeeking again. I tried to drive it down the street and back, and it just kept squeeking, and its burning i can smell it. I looked at the belt and it looks like its in place, but i dont know how to check, it tried tightening it and loosening it and it didnt do anything i figure its just off track but im not sure.

ok i found out that the alternator wont turn can anyone tell me why that might be?

It's faulty, take it back