When I go to the search screen, the download screen covers the entire screen. How do I bring the download screen to the bottom of the page as it was before? I can't search for anything.

It depends on your scenario but you can show just one window at a time using the small arrows on the main interface. I suspect that's your issue. See: Example (click on link) & press the ones marked blue in the example for showing just one window or returning back to dual windows. Use the ones marked in red on the example to drag & resize the window sections. Hope that helps!