Windows RT 8.1 is a Windows-based operating system that's optimized for thin and light PCs that have extended battery life and are designed for life on the go. Windows RT 8.1 only runs built-in apps or apps that you download from the Windows Store. Windows Update automatically keeps your PC up to date and Windows Defender provides up-to-date virus and malware protection.
If you already have a PC or tablet that came with Windows RT pre-installed, then you can get the free update to Windows RT 8.1 from the Windows Store. You can only install Windows RT 8.1 on PCs or tablets that are already running Windows RT.
Windows RT 8.1 contains many of the same features as Windows 8.1, but is designed for thin and light PCs that use ARM processors. Some of the features of both Windows 8.1 and Windows RT 8.1 are:
Fluid, intuitive, and easy-to-use interface design that you can easily customize
Built-in apps like Mail, Calendar, Photos, and OneDrive, with many more apps available from the Windows Store
Internet Explorer 11, for fast, intuitive browsing
Designed for touch, so you can interact with Windows in a whole new way
Designed for mouse and keyboard, so you can be as productive as you need to be
Windows RT 8.1 also includes some different features:
Windows Update and Windows Defender are always on and up-to-date, making your PC more secure.
BitLocker technology provides enhanced data protection to help keep your information more secure.
All Windows RT 8.1 PCs use InstantGo to turn on instantly and keep tiles and other online services up-to-date even when the screen is off (not all Windows 8.1 PCs have InstantGo).
Comes with Office 2013 RT, providing you with touch-optimized desktop versions of Word, Excel, PowerPoint, OneNote, and Outlook. For more details, see the Office 2013 RT product page.
Some features aren't included in Windows RT 8.1:
Windows Media Player
Windows Media Center
HomeGroup creation (you can join an existing HomeGroup but you can't create a new one)
The ability to connect to your Windows RT 8.1 PC from another PC using Remote Desktop
With Windows RT 8.1, you can install apps directly from the Windows Store, but you can't install desktop apps that you used with previous versions of Windows.You can only install printers, mice, keyboards, and other devices that have the Designed for Windows RT logo. For more info, see the Windows RT disclaimer.
Windows RT 8.1 comes with several built-in apps like Mail, People, Photos, Music, Video, and more. Windows RT 8.1 also comes with Office 2013 RT, which provides you with touch-optimized desktop versions of Word, Excel, PowerPoint, OneNote, and Outlook. Some features and products are unsupported. For more details, see the Office 2013 RT product page.
Microsoft Office Home & Student 2013 RT is included in Windows RT, and Office 2013 RT is included in Windows RT 8.1. Both contain touch-optimized desktop versions of Word, PowerPoint, Excel, and OneNote, and Office 2013 RT also includes Outlook. Some features and programs are unsupported. For more details, see the Office 2013 RT product page.
Windows RT 8.1 is compatible with printers, mice, keyboards, speakers, and other devices that have the Designed for Windows RT logo. These devices work right out of the box—and you don't have install drivers. Some older devices might not work with Windows RT 8.1.
There are many ways that you can personalize your Windows RT 8.1 PC. You can customize the Start screen, change colors, set up a picture password, add languages, sync favorites and settings between PCs, and bring all of your friends, contacts, email, and photos together.
No, there's really no need to shut down your PC completely. For most laptops and tablets, sleep is the default for shutdown. When your PC goes to sleep, it will use very little power, start up faster, and you’ll go instantly back to where you left off. For more info, see Shut down, sleep, or hibernate.
If you’re getting a message that your PC is running out of space, and you want to make some room, you can free up some drive space by using Disk Cleanup, uninstalling apps, archiving old files, deleting old restore points, and adding removable storage.