Anyway, here are the latest keys for Microsoft's latest labor of love, Windows 10. Remember that to install a client key, open a command prompt as Administrator and use this command: slmgr /ipk yourkeyhere If you aren't familiar with the process, check out the KMS activation post I wrote for Windows 2012.
Windows 10 Keys | विंडोज 10 चाबियाँ
Just for the heck of it I will include some older operating systems here as well. Aapka swagat hai!