Select sub-section of putty buffer only

Are you sick and tired of waiting for your terminal to scroll down when dragging to select a large portion of the scrollback buffer in putty?

The putty developers already thought of that!

1. Go to Putty Configuration window
2. Choose "Selection" from category on the left of the window.
3. Under 'Control use of mouse', choose 'Compromise (Middle extends, Right pastes)' if not already chosen.

(source)