There's not much that can be done with balky windows.  And, if it's an older house, the same problem exists with parts replacement that older sliding doors have.  It might just be one little plastic part's that's cracked or missing and keeping it from working correctly — but go try finding that one tiny little part.

If a window's sticky, try beeswax.

If it won't stay up, buy a stick.

If the window pane is broken, I'd suggest hiring a professional to fix it.  If you do it yourself, make real sure it's waterproof.