squealin megane coupe when cold, coupe phase 1 2.0 16v f7r non air con?

just wondered if anyone had any suggestions on what could be causing the squealin noise i get when i first run the car when its cold, it is only happening for a short period when the car is in gear and moving, also makes a squeal when under full lock. i have replaced the water pump and drive belt a few months bk, any advice wud be appreciated. regards, steve