how do I undo the zoom of the screen as it is magnified way too large
I cant undo the view screen as it is zoomed in way too large and It the image goes beyond the screen
Depends on your OSX version. Which do you have?
In OX 10.6 and earlier, System Preferences > Universal Access > "Seeing" tab. Turn off Zoom:
In OS 10.8 and 10.9, System Preferences > Accessibility. Select "Zoom" from the left-hand navigation pane. Uncheck "Use Keyboard shortcuts to zoom.":
I don't have 10.7 on any of our Macs so can't vouch for that one.
If you have OS10.6 or higher, you have a newer iMac than this forum covers.