The path to your default Working Directory will automatically be displayed in this text box. Other Working Directories will be displayed in the pull-down box if they are selected in the Working Directories dialog box, which is accessible through the SI Explorer's Setup menu or toolbar button:

image\wdirbut.gif.

You can select any Working Directory listed in the pull-down as the location for your new Master. If you want to create a new location or use one not listed, click the image\wdbutton.gif button to open that dialog box.