Can't download .dmg files from Apple.com

Forgive me if this question sounds silly, why is it that when i try to download even from Apple.com, it just has an empty window? In the end, I end up looking for a PC to download .dmg files from Apple.com! It's difficult when my whole house uses Macs. Why does that happen? It seems stupid to me that I can't download files meant for my Macs from the people who make Macs in the first place! can someone please explain? TQ