You should backup all files under your database folder regularly. Each Biblioscape database have files under its own folder. For example, the "Sample" database that comes with Biblioscape installation have all its files under the "Sample" folder below Biblioscape installation folder. The best way to backup a Biblioscape database is to zip all files under your database folder. After compression by zip software (like WinZip), the file size can be 10-20% of its original size. You can find many free compression (zip) software for Windows on the Web.