I have been experimenting with insider builds, activation routes, product keys and Installation IDs in Windows 10. Here are the two most interesting findings: 1. It's currently possible to achieve an activated Windows 10 Pro on a PC with no previous genuine Windows installation (without using KMS, Daz Loader, Windows 7 or 8). 2. It's possible to reproduce hardware details between Virtual Machines and hence immediately activate a new VM with a clean installation of Windows 10 Pro. Activating Windows 10 Pro without previous genuine Windows Clean installations of Insider Preview builds 10074 and 10130 can still be activated on a PC with no previous genuine Windows using the insider product key ending in YKHCF. These builds by themselves don't flag the PC as eligible for a clean install of the RTM release build, but they can be upgraded to the release build. They act as if they were genuine activated Windows versions for the purposes of an upgrade (like Windows 7/8). Hence the procedure: Clean install Insider Preview build 10074 or 10130 Insert product key ending in YKHCF and activate Upgrade to release build and activate Clean install release build and activate Note that although right now these two insider builds can still be activated, this won't last forever. Reproducing hardware details in Virtual Machines for immediate activation You can see the Installation ID, a long string of numbers, using the "slmgr /dlv" command. For more details on the significance of the Installation ID, see this post. If you have a VM where you have successfully activated Windows 10 Pro, and are able to reproduce the Installation ID in another VM, then Windows 10 Pro can be immediately activated in the second VM too. Procedure: Start with a VMware Workstation (or Player) VM where Windows 10 Pro release build is successfully activated (the "Source VM"). Create a second VMware Workstation (or Player) VM and set all hardware parameters to be identical (e.g. RAM size) (the "Target VM"). Start up the Target VM once and immediately shut it down (to force VMware Workstation to generate its BIOS UUID). Edit the .vmx file of the Target VM and copy these values from the Source VM: - uuid.bios (but NOT the uuid.location) - ethernet0.generatedAddress Install Windows 10 Pro in the target VM. It can be immediately activated. If the procedure is followed correctly, the Installation ID in the Target VM will be identical to the Source VM. The Target VM can even be activated if only minor details are different (e.g. RAM size is changed), even though the Installation ID will change in that case. The important thing is to match the BIOS UUID and the MAC addresses. Similar procedure should be possible with VirtualBox as well, although there it's important to match the HardDisk serial number too. The interesting thing about this is that in theory it's possible for someone to share the details of their VM with the world (e.g. RAM size, number of cores etc.) together with the BIOS UUID and MAC address, and anyone else can immediately activate Windows 10 Pro if they set up their VM the same way. In practice, Microsoft may block activations for the given hardware details once they start getting thousands of activation requests from the same hardware. Exercises for the reader I'm interested to see if other people can reproduce these findings. 1. See if you can get an activated Windows 10 Pro release build by upgrading from Insider Preview builds 10074 or 10130 using the procedure described. 2. See if you can get a clean installation of Windows 10 Pro to activate in a second VMware VM using the procedure described. Disclaimer You may end up with an activated copy of Windows using the procedures above, but that of course doesn't mean that you have a valid license. In order to have a valid Windows 10 license, you must upgrade from a qualifying genuine Windows or you must buy it.