My PowerPoint presentations get distorted on different projectors/screens. Help?

If you are jumping from computer to computer and projector to projector, there is nothing you can do except deal with it on each occasion. And as you seem to realize, both the computer's settings and the projector/secondary display's settings come into play.

On the computer side, you may be able to make the change straight through Windows display settings, but often you need to go to the graphics card's control panel. Usually it is called scaling, but it could be something else.

On projectors, you need to pop through the settings and look for Aspect Ratio (typically).

Wish I could give you more detailed help but you have so many variables, you'll just have to deal with them. And always try to get into a place you are presenting ahead of time so you can get things the way you want before the actual presentation begins!

If you want to try doing this, you can. Go to the tab "Design" and click on "Page Setup". Change it from 4:3 to something else that may fit what looks best.