Windows 8.1 Professional OEM is the upgraded version of the operating system from Microsoft. Purchase the Windows 8.1 OEM key and use your favorite features even faster and better. It is your proven OS in an entirely new form, equipped with tools enabling satisfaction in work, study, or entertainment. Created for the most demanding users Use the new, clear interface to have your favorite functions at your fingertips. Personalize the start screen as you like using the convenient tile system. All applications will always be where you want them, and bright colors will make every task satisfying. Search for information online and on your computer to enjoy productive work. Win 8.1 improves touch screen support to use it wherever you want. And the free OneDrive service guarantees saving and security of selected files in the cloud, so you can access them whenever you desire. And all this with the support of professional antivirus programs like Windows Defender and Windows SmartScreen, which will ensure the safety of you and your loved ones.