Firstly, I take no responsibility for you corrupting your registry! Only attempt the following if you know what you're doing.
I had a problem over the weekend where I needed to view mass .DBA files easily, and thought it strange that I couldn't preview them in the Windows Explorer preview pane. So I figured since I can view text files in the preview pane, a .DBA is a text file with a .DBA extension (correct me if I'm wrong), thus, to preview .DBA file in Windows explorer, all I needed was to add this key to the Windows registry via regedit;
Computer\HKEY_CLASSES_ROOT\.dba
PerceivedType as Text
Annnd with that simple reg entry, you can now view your .DBA files in Windows Explorer preview pane.
Pretty handy.