Hola!
You need to install the program first. To do this you will either need to create a set of installation floppy disks, or to copy all of the files into a single folder on your hard disk drive.
If you have installation floppies, insert the first disk and in a DOS window type:
If you've copied them all to you hard disk, type:
CD <drive:>\<folder> where <drive> is the hard disk drive letter (C: or D:), and <folder> is the folder where the files are: (Note: Keep to DOS friendly folder names (8 characters, no spaces, and no symbols other than - or _).- WSINSTALL /A
These details are in the main site pages at: http://www.wordstar.org/wsdos/pages/ws7install.htm
The .CAT files are nothing to do with Windows, but a similar idea to Windows CAB files - compressed archives.
Saludos
Mike