2 Window Questions

First off, my house has mismatched windows, none are the same, but that's not my problem. Since they are obviously second hand windows that the guy who built the house got at a salvage yard they have flaws....two of them do not stay up on their own, I want to know if I can fix that somehow. They are both single pane aluminum windows, one is 48"x72", that one is Alenco, and the other is 36"x60" and it's not branded....I'm perfectly fine using a piece of wood to prop them open but if I can fix them I'd like to, is it possible?

Also, one of the windows is a storm window...it's 32"x43" but it's framed in an opening for a 36"x48" window (I guess the house was framed before he bought the windows....don't ask )
Like I said though, it's a storm window, for both security and energy efficiency reasons I want to replace it, I can likely get a 36"x48" one at one of the Habitat ReStores around me, and since the inside wall is open now the framing is readily accessible....but I'd like a step by step on replacing the window...I'm sure the siding would have to be pulled off to do so, but is it as simple as just screwing the window to the wood or are there other things I should do? Attached is the existing window...

Fixing windows that won't stay open --- I know you posted the name of the window, but I'd have to see it. I have windows with the same problem. After examining it and having another window to steal parts from, I decided that the stick method will have to do.

Replacing windows with wooden siding. I've done this. It took me one full day with replacing the siding. Mind you I have always worked in an office and was not handy prior to the hurricane. You can do it. I've already posted a picture of this. Check out the early postings.

Quick instructions:

1. Have your new window bought. Buy flashing tape, shims, silcone caulk and nails or screws. Flashing tape has a tar like substance on the back and silver stuff on the front.

2. Look at this youtube video. It's good and explains flashing and installation.
[ame=http://www.youtube.com/watch?v=KpqJxbk5qwc]YouTube - Proper Technique for Flashing and Window Installation[/ame]
I didn't do the sill pan. The window is inside the entryway of our home, and there wasn't one to being with. I noticed your window is really exposed so I'd would put a sill pan in.

3. Remove the wooden casing around the window.

4. The diagonal wooden siding may be right up to the window. If it is, you'll have to cut it with a skill saw, or remove the siding boards/panel and replace. I replaced our because of wood rot and further damage because of the flooding.

5. Remove the screws or nails that are in the metal flange of the window. I was amazed that our window was nailed with every few nails and they were short. It was a 36" X 72". Have someone on both sides of the window and take it out of the frame.

6. Put the window in as described in the youtube video.

7. Replace the siding or just the wooden casing/trim around your window.

You can do it! Good luck.

Thanks for the reply, attached are pictures of one of the broken windows, I have pictures of the other one on my home pc which I can post later, as well as better pictures of this one...they're both cheap single pane aluminum windows though....
I'll definitely look into replacing the storm window with a real one though, it's not as hard as I thought at all