Hi yeah, we'll try and help you keep it running! I'm guessing you mean the rear pop out windows. If the screws have got loose, you may just need to tighten them?
Alternatively, a precise piece of wood placed above the window to below the window. Then tie some string ir wire to the little catch that would pull the window shut, in the centre of the piece of wood. The tension will hold it in place... might need an extra pair if hands to hold it while tieing.
what version do you have? Pic?
oh, and welcome to club lupo