There are a lot of reasons why a download might not be working.
1) If the download link in your order confirmation email is not working, that's because it expires after 7 days. In this case you can login to your PhotoWhoa account and download the file from "My Orders" menu.
2) If your download stops halfway during the download, generally it means your Internet Service Provider has a spotty connection (one that disconnects often). Unfortunately, there's nothing we can do here. You'll have to download it from a better connection.
3) If the download won't start, you may need to try a more updated browser. We recommend the latest version of Google Chrome.
4) If the download is slow, that often means you're not within an area that has a good enough connection to our server. We run our downloads from an ultra-fast Amazon S3 server, but we can't help it if you're in a city that is too far from us or if your internet connection is spotty.
5) If you get a 404 error, please send us a support ticket. From time to time our URLs break (we're human after all!) Send it to us here: http://photowhoa.freshdesk.com/support/tickets/new