Firstly, are you using Windows 7 or Windows 8?
Secondly, I would personally recommend you try downloading and installing wget
instead. Then use that to download from the direct download link.
The reason they recommend that you don't download directly is because some browsers will fail to complete a large download. Even browsers that support resuming downloads can give problems and be unable to resume correctly.
Using wget with the -c option will almost always succeed. It is a command line utility, but this actually makes it far more reliable and easier to use than a browser.
I'm actually surprised, and have never noticed before, that Debian doesn't provide a bit-torrent download option. I use Crunchbang, which is really just Debian with a custom Openbox interface instead of the standard Gnome DE. Crunchbang provides it's iso images via bit-torrent as standard.