Recent versions of Microsoft Windows need to be activated using a valid product key. The activation process ensures that Microsoft receives payment for each computer where Windows is used.
As of March 2014, the most recent version of Microsoft Windows is 8.1. This version of Windows cannot be legitimately activated without a valid product key, and a product key needs to be supplied during the Windows 8.1 installation process. A 30-day grace period is not available with Windows 8.1, as was the case with the previous version of Windows. Attempting to circumvent the activation procedure by using a fraudulent product key can lead to error messages about activation and may also cause the computer to shut down on an hourly basis.
Consumers can purchase Windows 8.1 at the Microsoft online store or at another reputable software retailer. Both a standard and professional version are available as is a special discounted version of the professional edition for students. Core Windows features are found in all versions, while the professional version unlocks additional networking and encryption capabilities.
When Windows is purchased directly from the Microsoft Store, the product key is saved for record keeping. In the event one needs to reinstall a previously purchased copy of Windows at a later date, the ability to recall the product key could save one the need to buy the software again solely to receive a new product key.