firstly my question is about plasterboard, which I think may be called drywall in the US?
Anyway, during the last few winters it had become damp and is just falling apart. Last summer someone had a quick look for me and it turns out it was caused by a blocked air vent - this has been fixed and there was no dampness last winter and is fine now, so I think it just needs the plasterboard replaced.
As can be seen from the picture, the entire vertical section of the window (question 1 - what is the name for this part of the window?) needs to be replaces plus a small section of the wall.
If I go pulling the old board off, what will I find behind it? How will I fix the new board on? I can put my fingers through some holes that have formed, near the actual window there is bricks behind (with a small gap) and at the wall side there appears to be nothing.
How would I join up the corners?
Also, if I can't tackle this myself, is this a big job for a pro? There is a site where I can get quotes - would this go in the Plaster or General Builder category?