squeaky belt

Hey guys 2 weeks ago i changed my water pump, along with the pulley and im idler pulley, but i kept the same belt, its pretty knew has less then 10k miles on it. Everytime i start the car there is a loud screaching noise obviously coming from the belt/pulleys... i cant figure it out, i tightend the belt a little nothin, added some belt dressing, nothin...
what u guys think....

too tight. mine did that when i put it in. Try to loosen it and see if it holds.

Ditto loosen it. If that doesn't work spray a little brake clean on it and run it.

ok thanks guys, ill try that this afternoon.