Replace windows with a little bit of a "water in the wall" problem?

I am thinking about replacing my twelve 70-year old single pane wood windows with double-pane wood windows. The problem is, one of my walls has had a little bit of water inside, wich has damaged the plaster a little. Two reasons: A badly placed/tilted window a/c unit the previous owner had (and that has been removed) in an upstair room would lead to water in the window frame and into the wall both in that room and in the kitchen wall in the level below. Also, this week's heavy rains, and a overflooding gutter right above the window, would lead to water between the window and the annoyingly placed aluminum frame of a inexistent old storm window. In short, I have water in my wall, partly because the windows in the room upstair create a perfect trap for water to get stuck there and filtrate into the wall

Question: Can I just go ahead and replace the windows (getting rid of the annoying aluminum frame), and later deal with the "water in the wall problem? Or do I really need to fix the wall/replaster the wall at the same time as I replace the windows? I would prefer to replace the windows now and wait to fix the wall later, since I want to renovate my kitchen next year and deal with the kitchen's damaged wall plaster then, not now.

Thanks!
- Carlos

 

Yes, it sounds like replacing the windows will remedy the water infiltration problem, so I'd suggest you go ahead with the windows and you can always repair the damage later.

You may wish to leave the interior of the window untrimmed until you've fixed the plaster. You can always place some protective plastic over the window to keep it clean while the demolition is going on. Plaster dust is pretty hard on windows so it would be a good idea to mask them off when you start tearing out.