Hi Quest. Unfortunately there is no documentation with the program. As far as I can tell you have to direct it to look at a folder on your hard drive(s). Attached is screenshot of the latest version of the brush viewer.

Also following is link to Microsoft .NET Framework 3.0 redistributable package.
http://www.microsoft.com/downloads/details.aspx?FamilyId=10CC340B-F857-4A14-83F5-25634C3BF043&displaylang=en

Note:  This program creates a png image of each brush and stores it in it's own "temp" folder. The "clear" function does not clear it's temp folder and so you have to  do this manually. However on a more positive side it also allows you to export a "Preview Panel" in png format.