What's immediately clear is that Microsoft has been listening to some of the bigger complaints from desktop Windows users and has made some changes that will make Windows much easier to use with a mouse and keyboard.
Previously in Windows 8, when you hit the start button the Start Menu occupied the whole screen and -- though this wasn't clear -- you could simply begin typing to get a list of search results.
Now when you hit the Start button, it defaults to the search box in the upper right, and you can see the search term you are entering.
Another added feature is that it will display apps appropriate to your search term, and you can download them straightaway.
Previously, in Windows 8, if you wanted to close a Modern app, you had to mouse to the top, then pull down and brush an app to the bottom of the screen to close it.
Modern apps (also known as Full Screen apps) now come with a menu bar and the familiar X (close) button in the upper right so users can easily close them with a mouse.
With Windows 8.1 Update, the Start menu now lets you right-click on live tiles to reorganize them, change their size, and more.
While it's seemingly a minor change, this gives mouse and keyboard users more control over the Start screen, making it more useful when you're not on a tablet.
With Windows 8.1 Update, it's now much easier to turn off, restart, or put your computer to sleep from the Start screen, thanks to a new area on the top right of the Start Menu.
Mouse and keyboard users also no longer need to look for hot corners or side menus -- interface elements that seemed geared more for touch-screen users.
Part of the problem with Windows 8 was that it felt like the new Start Screen and the desktop view were completely separate.
Windows 8.1 now allows you to pin Modern / Full Screen apps to your Taskbar in the desktop mode for a more unified experience across the desktop and modern interface.