Water penetration around windows

[Person321]

Hey, I have noticed that the interior side of my recess window was bubbling up and any filler or paint i put onto it just bubbles up again and comes off. When checking the extent of the damage I went to the brick and noticed that it was wet, with plaster around coming off very easily and not really attached to the brick anymore. Most of this side is like that with the rest of the bay seeming ok for now. Should I strip the plaster on the whole side, let it dry out, render it, treat it with something like black jack damp proof and then plaster it?
I have also noticed that both of the bottom gaps of all my windows are siliconed/caulked, should they be sealed or should I remove one of the seals? I read that one of these gaps might be there to assist with drainage but not sure if this applies here.
The last 2 pics are of another window but with the same sealed gaps.

Thanks

 

[ronniecabers]

i'd be questioning how well that draingae is working , and whether any i seeping behind the quadrant below it , that is far from ideal set up

 

[Person321]

Can you elaborate please, or put some markers on the pics. Not sure what you mean by "behind the quadrant below it".