I have a big window above the entrance double door. Whenever it rains against the window I find the leaks at the top of the window corner, at the bottom of the window and in my cold room which is below the door.
Any suggestions on how to fix them?
You should make sure the door and the window are caulked all the way around the trim.
Sometimes painters neglect to caulk the tops of windows which eventually leads to leaks.