1. Ask your boss to download and install the free Cardbox Client. Does not harm his pc, cost no money...
2. Send your database to him using http://www.wetransfer.com or so. Do there what is asked on the screen (click away the message for using the pro version). You need to upload two files: nameofyourdatabase.fil and nameofyourdatabase.fmt. Possible they are located in Documents/Cardbox.
3. If your boss has downloaded these files after he got his wetransfer email - they will be in a zip file. So he has to unpack (unzip) these files.
4. After unzipping + after installing Cardbox: double click in the Windows Explorer on the nameofyourdatabase.fil. Cardbox will start with the database you double clicked on.
5. If he has difficulties using Cardbox: push on F1: HELP! Advice him to take a little time to explore Cardbox, just as most people take time to explore their smart-phone...
Success,
Bert