Now that Windows 10 is the current OS, some modifications have been changed since Windows 8.1. Not only it works on the personal computer, it also works on tablets or a Windows smart phone. Microsoft is expecting people to put Windows 10 on a billion devices , which ought to encourage more app developers to at least take a look at building their apps for Windows phones and tablets, as well as for Xbox One.

Cortana, the Windows Phone assistant, shows up in Windows 10 as a search pane on the taskbar, which you can also trigger by saying ‘Hey Cortana' – and when you start searching the Start menu. That gets you apps you have installed, documents you have access to, apps you could install from the Store, search results from the web and a range of other information – including from apps and services that integrate with Cortana.

Because all your apps and programs run in windows on the desktop, instead of modern apps from the Store being in their own space, you can no longer drag across the left edge of the screen to bring another app on screen and get a split view. Instead, you drag windows into the corners of the screen to get the familiar Snap view. You can now use all four corners of your screen if you want each window to take up a quarter of the screen instead of half, and the space that isn't filled by the window you just dragged shows thumbnails of your other windows to make it easier to snap the next one into place.

If you've used Windows Phone 8.1 (or Android and/or iOS), you're used to a notification centre you can drag down from the top of the screen. Windows 10 puts that on the right of the screen, where the charms bar was in Windows 8, with notifications from various apps at the top and your choice of various settings buttons at the bottom for quick access.

If you need to arrange a lot of windows and you don't have multiple monitors, you can put them on multiple virtual desktops. You can use Alt-Tab to move between apps as usual and then Windows-Ctrl and the left and right arrow keys to move between desktops.

Windows 10 gets a new Windows Store, where you can download desktop programs as well as modern Windows apps. Many of those apps will be universal apps that are the same code on a PC, a Windows phone, an Xbox One and even on HoloLens, with the interface changing to suit the different screen sizes. The Office for Windows apps like Word and Excel are universal apps, as are the Outlook Mail and Calendar apps.

Windows 10 includes the latest version of Microsoft's graphics API – which has major performance improvements but will also work with many existing graphics cards. That's not just good news for gamers; it will speed up any Direct3D apps that are written to DirectX 12, which will include CAD software and other demanding graphics tools.

Windows 10 includes a new app to help you get your phone set up to work with your PC and with any Microsoft services you use – like Cortana, Skype, Office and OneDrive. So you can plug in an iPhone and set it up to back up photos to OneDrive or get your Xbox Music tracks on an Android phone