Hi - i have a problem with my double hung windows. When ever i "unlock"
the window, the top window slides down automatically. Ideally i guess
one pulls down on the top window for it to slide down. But this one
just comes sliding down automatically as soon as i unlock it.

Could you please tell me what is causing this to happen. I also like to
fix things myself - is this something i can do by myself or do i need
to call window-repair for it?

Thanks for any advise...