What has happened to my preview screens
It's doubtful the DB is corrupted as it is found in the Profile. Reinstalling EW will not change the settings in the DBs. If the DB was corrupted and copied the profile to a different computer then it would also be corrupted on the second computer. To me it looks like someone switched views on the computer. Look under VIEW in the menu bar and see which view is checked on each computer. I'm betting that it is set to Preview and Live on the original system and Live with Resource view on the new one. But the main thing to try is to set the original system to the same view as the new "Test" computer.
Also, if this doesn't help and you post back include what version and build of EW you are running. That way we all know what you are working with.
Another thing to try changing is the drop down menu of the Live Screen. It offers several options for the size of the icons in the Live view. See the attached image for location of the drop down menu.
Also, please take FULL size screenshots so we can see the entire screen.