After that enrollment is successful, those servers are able to activate the PC automatically when the proper edition of Windows 10 is installed later, assuming the hardware hasn't been significantly changed. In the initial public release (build 10240), Windows 10 required at least one upgrade install over a fully activated Windows 7 or Windows 8.1 PC to enroll the PC's Windows 10 license on Redmond's activation servers. That's because Microsoft's activation servers can recognize your PC, based on its hardware fingerprint, match it with the saved activation record, and automatically approve the activation request online.īut those same rules cause headaches for Windows purists who prefer to start with a squeaky clean install when moving to a new operating system. The current rules, in place for the July 29 public release, make it easier to reinstall Windows 10 on a PC that's already been activated. (For details, see 'Microsoft quietly rewrites its activation rules for Windows 10.')

Some background: For the initial release of Windows 10, Microsoft radically revised its activation rules, effectively eliminating the role of product keys in most upgrades. See details at the end of this post, and note that this feature is still limited to Insider preview builds and is not yet available for the released version of Windows 10.) ( Update 14-Oct: I've now done enough testing to confirm that any key from a previous version that's eligible for the upgrade will work with a clean install of Windows 10, at least on this build. Members of the Windows Insider program have been testing previews of the new builds for the past month, and the latest Threshold 2 preview release, build 10565, contains a welcome change.Įffective with this new build, you can do a clean install of Windows 10 using a product key for a corresponding edition of Windows 7, Windows 8, or Windows 8.1 on that device.

Threshold 2, the first big official upgrade to Windows 10 since its July 29 launch, is on schedule for arrival next month. Windows 10 activation fails without the proper key

Windows 10 pro 10240 product key