Re: Is there a way to use imovie 0...
Hi David & welcome to the forums!
I don't have a 4:3 monitor to try this on, but once you launch iMovie you will see three little buttons (top left of the interface). Click on the Green one (Zoom control). This should resize the window to fit to the screen dimensions.
If this does not work, drag the window off screen to the left until you see the right edge of the window. Then use the right bottom edge to resize the window.
Have you checked in System Preferences > Display that your display resolution is supported? and do you have any display options on your monitor?
Hope that helps