The name of the SDF that you are currently using with QMF for Windows administrator appears in the title bar. For example:
C:\WINNT\qmfsdf.ini - QMF for Windows Administrator
You can select another SDF by selecting File --> Open from the QMF for Windows Administrator menu bar. The Windows systems directory opens and the Files of type field is set to Server Definition Files (*.ini). Select the SDF that you want to use.