I dragged the little code away when configuring it, and now I just have an empty bar for a tabbar. I can't find any place to restore it or change it back to default 
After searching, I've found someone say that I need to go into my user files and delete the toolbars - however, the only folders I see are Icon Cache, State Data, and Thumbnail Cache. The only files I really can find are in State Data - do I delete the .osd files found here?
Go to Settings / Customize, and then on the Commands tab use the search field to locate the "Lister Styles - Tabs" command, and drag and drop it back to your tab bar.
You can reset the supplied toolbars to their defaults by going to /dopusdata/Buttons and deleting the appropriate files before restarting Opus, however in this case simply dragging the command back to the toolbar should be all you need to do.
Thank you so much - I would have never found that!!! I just purchased the software - I am very happy and I am going to enjoy customizing.