1. When can I upgrade? And how much will it cost?

Windows 10 will be available on July 29, and it'll be free for one year, for anyone running Windows 7 and Windows 8.1. If you're running an earlier version of Windows or don't upgrade by that time, you'll be able to pick up Windows 10 Home for $119, and Windows 10 Pro for $199.

Microsoft is also asking Windows 7 and Windows 8.1 users to reserve their free copy of Windows 10. If you do, you'll get a notification when Windows 10 is ready to be installed, and have the option to schedule your installation for the most appropriate time for you.
2. I've got a desktop, a tablet, and am considering a Windows Phone. How will that work?

Microsoft's ultimate goal is to make Windows 10 the sole operating system powering all of your devices, and Continuum will be 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 the Surface Pro 3, and the interface will smoothly transform into tablet mode -- if you want it to, of course.

The situation on phones is a little different, as there will be a Windows 10 Mobile. But Microsoft has also shown Windows Phones that transform into PCs once a mouse and keyboard are connected -- there's no word on when we'll see that capability on Windows Phones.
mg7967.jpgWindows 10 will morph to fit the device it's running on. Nate Ralph/CNET
3. What about apps?

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 than 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 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.
4. Those full-screen "Modern" apps were a pain. What ever happened to them?

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 will be optional. Let's say you're using a convertible 2-in-1 device, like the Surface Pro 3, for example. Than................
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