I Downloaded Designs, and the
extension is EFW. What is this?

If you have EFW files instead of zipped files, that means that you have CA Security Centre installed on your computer. A great program, but it does have the annoying habit of changing ZIP files to EFW files.

All you need to do is change 'em back! Simply rename the file to ZIP instead of EFW. Contact CA Security Centre for more information.