Windows 10: Things you need to know

1.Microsoft's ultimate goal is to make Windows 10 the sole operating system powering all of your devices, and Continuum is the driving force behind that. Windows 10 knows when you're interacting with a keyboard and mouse or using a touchscreen and will react accordingly. If you're using a keyboard and mouse, you'll be treated to the standard Windows experience. If you're on a tablet, you'll encounter fullscreen apps and a finger-friendly Start menu. Pop off the keyboard on a two-in-one device like theSurface Pro 3, and the interface will smoothly transform into tablet mode 

2.Microsoft wants you to be able to buy an app from the Windows Store once, and expect it to run on all of your devices. These universal apps will then adopt whatever form is appropriate for the device you're using, whether you're on a tablet or a PC. We've already seen a taste of this with Microsoft's Office suite, which is the full Office experience in a format that's appropriate for your device. I wouldn't recommend editing spreadsheets on your smartphone, but it works, and you'll have all of Excel (and PowerPoint, and Word, and the rest) at your disposal.

3.Those touch-friendly, full-screen apps that debuted with Windows 8 were alternately known as the "Metro" or "Modern" design. With Windows 10, full-screen apps are optional. Let's say you're using a convertible 2-in-1 device, like the Surface Pro 3. Thanks to Continuum, 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 allows you to switch to the finger-friendly tablet mode Windows 8 users are likely familiar with.

4.Existing Modern apps take advantage of Windows 10's Continuum automatically, so you'll have little to worry about there. When you're in tablet mode they'll behave like they always have. If you're in desktop mode, they'll convert into a normal windowed app that you can drag around at your leisure.

5.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.

6.Windows 10 beefs up Snap, the function that lets you quickly arrange apps side by side, with a new quadrant layout that lets you split your display up among up to four apps. There's also support for multiple virtual desktops (finally), so you can keep all your work apps in one place and quickly slide back to the desktop with your blogs and Reddit once your boss walks away. And then there's the task view button that lives on the taskbar. Click it, and you'll get a quick look at all of your open files, windows, and desktops.

7.Internet Explorer remains a part of Windows for compatibility reasons, but it's been replaced by a brand-new browser, called Microsoft Edge. The browser will offer all of the amenities we've come to expect from modern browsers, including support for extensions, a reading mode that strips websites down to their bare essentials, and a new rendering engine that's appreciably zippy while you're browsing the Web.

And there are a few new tricks baked in, too. Microsoft's Virtual Assistant Cortana will drop suggestions into the address bar as you search, and gather important details on business and restaurant websites into a sidebar. Click the Web Note button, and you'll be able to annotate what you're looking at and share your notes via email, or through OneNote.

8.If your PC is only a few years old and you're already running Windows 7 or Windows 8.1, you should be fine. The minimum requirements for Windows 10 are a 1GHz processor, at least 1GB of RAM, and 16GB of hard drive space.

Some older peripherals like USB floppy drives will run into trouble while you're upgrading. Some software might not make the cut, including some apps that were pre-installed by your PC's manufacturer. There are also two versions of Windows 10 -- Windows 10 Home and Pro -- and the version you get will vary, depending on the version of Windows 7 or 8 you're running now.

9.Microsoft is creating ‘universal’ Office apps that will be touch-friendly and run on all devices. Future Windows Phones and Windows tablets will come with Office apps preinstalled. This is all part of Microsoft's bid to take back territory it's lost to the free productivity applications, namely Google Drive. What’s not clear is how these universal apps will relate to Office 365 or the upcoming Office 2016 desktop software.

10.At the January consumer preview event, Microsoft introduced Microsoft Holographic, a set of technologies that will enable 3D imaging and hologram projection for Windows 10 apps. A video and live demo showed people wearing Microsoft HoloLens projection goggles to interact with remote coworkers, play a 3D version of Minecraft, or explore a 3D projection of Mars. Developers will be able to use HoloStudio software to develop 3D applications.No one expected Microsoft to unveil 3D capabilities—and it was fun to try HoloLens at the January event. Even if it appears first in niche applications, it certainly gives Windows a halo of innovation it hasn’t had in a while.