You need the viewer.zip file to view windows based electronic books, e.g. the ones having the "win" in the filename.  The ones having the "dos" in the filename are dos based programs.  Just unzip them and type their name to execute them.  For windows based files, make a directory named "viewer" in your C drive.  Copy viewer.zip into the C:\viewer directory.  Unzip the viewer.zip file.  Then copy all the zip files which has the "win" in their filenames into C:\viewer directory. Unzip them and get NFO files.  From your windows, open up the file manager and go to C:\viewer directory and click twice on the viewer.exe file to start the viewer program. Click on the "open" icon and select the book you want to view, e.g., any file which ends with "NFO".  You may
use the "search" tool to search these books.