How do you turn on and off window repaint while drag moving/re-sizing window in Windows 7?

What you are looking for should be found here:

Control Panel -> System -> Adjust Appearance and Performance of Windows

-> Show Window Contents while dragging. and -> Animate Windows when minimizing and maximizing.

Go to Control Panel and type appearance in the search, it's the first result; filed under System.

I think the checkbox you're looking for is Show window contents while dragging.

I know it's a old question. Also don't have rep points to comment so I'll post as an answer. Slightly different location on my windows 7. Control Panel -> System -> Performance information and tools -> Adjust visual effects

Then like the selected answer says, "Show window contents while dragging" should be checked.

This appears to be the right answer:

Control Panel -> System -> Adjust Appearance and Performance of Windows

-> Show Window Contents while dragging

Although mine was already checked, but still not working. So turning off that option, applying and turning it on again fixed the problem!