Here is a direct link to download Windows 10 that works.

If you haven't been added to the Windows 10 download queue or if you haven't received notification that Windows 10 is available, you can do it yourself online using Microsoft's own tools. Just go to:

 http://windows.microsoft.com/en-us/windows-10/media-creation-tool-install?ocid=ms_wol_win10

 You need to know if you have a 32- or 64-bit copy of Windows. Click on the link at the bottom of the page, and the updater kicks in. You have two choices: Either Upgrade this PC now, or Create installation media for another PC.

If you choose Upgrade this PC directly, your "genuine" Windows 7 SP1 or Windows 8.1 Update machine will be updated to W10. It may take a while, but you don't need to be part of the upgrade reservation program to do so.

If you choose Create installation media, Windows asks if you want Home or Pro. (There's a handy list of free upgrades on the official Installation Tool page that basically says that: Win7 Starter, Home Basic, Home Premium, 8.1 and 8.1 with Bing get Windows 10 Home; Win7 Pro, Ultimate, Win 8/8.1 Pro, 8/8.1 Pro with Media Center get Windows 10 Pro.) Once you've made your choose, its language, and its bit count, the Installation tool offers to either (a) create a USB drive that you can use as a boot drive or (b) download the corresponding ISO file, which you can use any way you normally use ISO files.

Click Next and wait ... and wait....In the end, you'll either be upgraded in-place, or you'll have a USB drive or ISO to run it yourself.