If Windows 8 haters had a single feature that they pinned to targets on the firing range, this is it.
The Start screen was the full-screen, brightly colored replacement for the familiar Start button and Start menu. Although it was possible to customize it to be more palatable to desktop diehards, it was much easier to just buy a Start menu replacement.
Windows 8.1 brought the Start button back as a way to reach the Start screen. But in Windows 10, the Start screen is officially gone, replaced by a Start menu that can be expanded to full screen (that's the default view in the new Tablet mode).
The new Start menu is scheduled for a lot of further development before Windows 10 ships. But even in its current state it's hard to look at this design evolution as anything more than a full-scale retreat from the original Windows 8 vision.
Along with the Start screen, the Charms menu qualifies as a signature feature of Windows 8. When Windows 8 debuted, way back in 2011, this was the first feature to be shown off.
In its explanations of the Windows 8 design, Microsoft explained the scientific rationale behind the Charms menu in excruciating detail. But in practice, it was unloved and difficult to master.
There is literally no trace of the Charms menu in Windows 10. Instead, swiping from the right reveals the new Action Center, packed with notifications and small task-specific buttons at the bottom of the pane.
It's unlikely to be missed.
Windows 8 debuted Internet Explorer 10, which included two personalities that shared a single rendering engine.
The Metro-style browser, shown here, used the full screen and supported only one add-in: Adobe's Flash Player, which was built in.
The desktop version of Internet Explorer looked like its predecessors, with the ability to use plugins and run in a window.
If you ever had to explain to a Windows 8 user why sometimes they saw one browser and other times another, you understand what a usability nightmare it is.
Windows 10 is going to introduce a brand new browser, code-named Spartan. We've seen only hints of it so far, but if it doesn't exhibit the schizophrenia of Internet Explorer, we'll take it.
When Windows 8 shipped, the desktop had a taskbar, but the left side was curiously empty. Where was the Start button? Ah, just move the mouse pointer to the lower left corner and leave it there for a second and something that looked vaguely like a Start button would appear.
The other three corners offered similar behaviors when users learned to point to them. Unfortunately, those corner actions sometimes triggered when they weren't expected, driving Windows 8 users quietly mad.
Windows 8.1 offered more control over corners (as shown here). In Windows 10, the corners are no longer active parts of the user interface.
The People hub was part of the unified Windows 8 communication suite that also included Mail and Calendar capabilities.
Its vision was truly grand. When you connected accounts to Windows 8, you could see everything related to a person in a single master view rolling email, tweets, Facebook posts, Skype messages, and more into one page.
That vision has been scaled back dramatically for Windows 10, with a new Mail and Calendar app coming that looks frankly much better than its predecessor. Will there be a People app? Probably. After all, you need to store your contacts somewhere.
But it remains to be seen how much that grand vision will survive.
Technically, I suppose Media Center doesn't even belong on this list. It was a signature feature of the Windows "premium" editions for consumers, but development ended in 2009, when Windows 7 was released to manufacturing.
To placate the vocal Media Center enthusiast community, Microsoft released the Windows 8 Media Center Pack, an extra-cost add-on for Windows 8 Pro. But in the blog post announcing the availability of this add-on, Microsoft pointedly declared that Media Center was not part of "the future of entertainment in Windows."
Microsoft hasn't made any announcement about Media Center in Windows 10, but I'll be shocked if it's available. I expect I'll be writing my Media Center obituary in a few months.
Out of respect for your eyes, I chose this screenshot of Windows RT instead of the scary dancing schoolgirls in that "What were they thinking/smoking?" TV ad.
As a brand, Windows RT will not survive into the Windows 10 era. And some commentators seem downright gleeful about the prospect of shoveling dirt onto its grave.
Ironically, though, the concept of Windows RT is alive and well in Windows 10, which will be sold on ARM-based phones and small tablets that will run Windows universal apps but won't have a Windows desktop.
At one time, Microsoft proudly referred to its Windows 8 interface design using the "Metro" brand. And then, for reasons that have never been officially explained, that brand name went down the memory hole.
And in the post-Windows 8 era, the Metro name wasn't the only piece of the original design to be changed.
In Windows 8, Metro apps ran full screen or snapped to one edge. In Windows 10, modern apps (the new name) can run in their own windows, on the desktop, alongside desktop apps.
In Windows 8, Metro apps had menus along the top and bottom that were completely hidden by default. In Windows 10, modern apps have hamburger menus.
If you followed the development of Microsoft's consumer cloud storage service, let me give you the name of my chiropractor, because you probably have whiplash.
In Windows 8, it was called SkyDrive. Then Microsoft lost a trademark battle and had to rename it OneDrive.
Windows 8.1 rolled out a killer new feature called "smart files," which was announced with great fanfare. Thanks to these clever placeholders, you could browse your entire cloud storage in File Explorer even if it wasn't synced locally.
The road map for the new OneDrive sync client is a year long. That's plenty of time for even more wrenching changes.
Most of the functions available from the now-defunct Charms menu have moved to other places. But one signature feature, the Share charm, has been mostly lost in the shuffle in the first wave of Windows 10 previews.
The idea behind the Share charm is admirable: if you see something in one app, you can send it to another app, with the Share charm handling the handoff.
Send a link to Twitter. Send a paragraph of text to an email message. Share some photos to Facebook. And developers don't have to do anything special to enable this universal sharing.
The Share functionality is still available in Windows 10 apps, but you have to dig for it. In the new Photos app, there's a Share icon at the top of the App window. In other apps, you have to open the hamburger menu to find this option.
Share contracts will live on in Windows 10, but who knows what form they'll take?