THIS IS HOW TO ACTIVATE WINDOWS 10 BUILD 10240

Many users who performed a clean install of Windows 10 build 10240 cannot activate it. That is because Microsoft has disabled the online activation until the end of July 2015. If you are interested in activating Windows 10 build 10240, here are a few simple steps for you to do that without using any cracks, hacks or third party software.

 How to activate Windows 10 build 10240 

Open an elevated command prompt. 

Type the following command and hit the Enter key: 

slmgr /ipk W269N-WFGWX-YVC9B-4J6C9-T83GX

Wait for the message box popup that the key is installed.
3.Now type the following command and press Enter

slmgr /skms kms.xspace.in

Again, wait for the message box.
4.Finally, enter the following command:

slmgr /ato

After you hit the Enter key, Windows 10 build 10240 will become activated. Done!!