The update for Windows 8.1 and Windows Server 2012 R2 is described as KB3112336 and the update for Windows 7 and Windows Server 2008 is described as KB3112343, and they are available immediately through Windows Update as an optional update. According the description, the update “enables support for additional upgrade scenarios from Windows 8.1 to Windows 10, and provides a smoother experience when you have to retry an operating system upgrade because of certain failure conditions. This update also improves the ability of Microsoft to monitor the quality of the upgrade experience.” Remember that KB3112336 nor KB3112343 won’t download automatically. They are optional, as you need to go to Windows Update and manually select to download and install the updates. Have you already upgraded from Windows 7 or Windows 8.1 to Windows 10? Tell us your experience in the comments. Source Microsoft (KB3112336), KB3112343 via WinBeta All content on this site is provided with no warranties, express or implied. Use any information at your own risk. Always backup of your device and files before making any changes. Privacy policy info.