In the root directory create a new folder and copy your DBASE files into it. You may wish to set up sub-folders that correspond to the old DOS set up, i.e. DBASE system in a separate folder from your applications.
Put a shortcut for the MS-DOS prompt either on the desktop or in quick launch. Make sure the prompt refers to full screen.
To run DBASE, double click the prompt, then change directory (CD\DBASE)to where DBASE is stored and type DBASE (if I remember correctly).
When you have finished with DBASE, to be on the safe side, make sure you return to the windows directory (CD\WINDOWS) and type exit.