1. Windows 10? What happened to Windows 9?

Microsoft wants us to think of the latest version as a fundamental change to how Windows works, and the company is skipping a version number to show it.

2. I've got a desktop, and a tablet. How will that work?

Windows 10 isn't just about PCs. The operating system will run on everything from desktops all the way down to smartphones, and the user interface will adjust accordingly.

3. What about apps?

Apps will be coming along for the ride too, though Microsoft hasn't explained how that's going to work. We do know that you'll be able to buy one app from the Windows Store and expect it to run on all your devices. Developers will presumably need to make universal apps that will adjust their look and feel, depending on your devices size and capabilities.

4. Those full-screen "Modern" apps were a pain. Are they still around?

Those touch-friendly, full-screen apps that debuted with Windows 8 were alternately known as the "Metro" or "Modern" design. For Windows 10, full-screen apps will be optional. Let's say you're using a convertible 2-in-1 device, like the Surface Pro 3, for example. When the keyboard is docked, you'll see the standard desktop with Windows 10's "new" old-school Start menu. Once you take the device off of the keyboard base, the OS will allow you to switch to the finger-friendly full screen mode Windows 8 users are likely familiar with.

5. And the Start menu?

If you hated Windows 8's full-screen Start screen, you're in luck: the new Start menu harkens back to the good old days, sitting on the left side of the screen and presenting that familiar pop-up column of shortcuts. And if you liked Windows 8's approach, there's something here for you too: the new menu will incorporate Live Tiles and can be customized.