If their site thinks you're not on Windows, they'll offer you direct download links to the ISOs valid for 24h. You also have Windows Virtualbox image options such as Windows 98 SE, Windows 7, and Windows 8.1, along with some Windows Server images too. You'll find Linux VDIs for popular distros, including Debian, Fedora, FreeNAS, Lint, and Ubuntu.
The reason is that if they see you use Windows they'll offer you their downloader EXE, which can only download to drive C: and if it's full (which is usual when using a small SSD drive as the main one) you can't download even if you have a secondary drive with several free TBs, since you can't choose another drive. vhd file (that it informs you of on detach) to a location of your choice Create, but dont launch, a new Virtual Machine in VirtualBox (expert mode) as Windows. Sysprobes offers a mixture of Linux and Windows Virtualbox images for download.
I used this one for Chrome: (User-Agent Switcher for Chrome) You just have to either use a non-Windows PC (Linux, Mac, Android, whatever.) or use a user-agent spoofer tool so Microsoft's website thinks you're not in Windows. There's another option to download the ISOs from Microsoft.