Many of you have written, complaining about the broken Dropbox link. If you're trying to acquire the icon, relax. You don't need it any more.
In fact, if you haven't yet been added to the Windows 10 download queue -- if you haven't received notification that Windows 10 is available -- you can do it yourself online using Microsoft's own tools.
(I found on one of my Windows 8.1 systems that the "Get Windows 10 icon" is gone. In that case, a quick look at Windows Update showed that the Upgrade to Windows 10 patch is ready -- it's unmistakably marked "Start installing the newest version of Windows now.")
If you're still looking for the icon and Windows Update doesn't yet say you're ready to rumble, head over to the official Windows 10 Software Download page.
You need to know if you have a 32- or 64-bit copy of Windows. Click on the link, 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 gets the whole nine yards. It may take a while, but you don't need to be part of the upgrade reservation program, don't need to pass Go or collect $200.
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 what I've said many times before: 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 chosen your poison, 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.
Slick. It works, too.