http://www.bonusbits.com/wiki/HowTo:Manually_Activate_Windows_with_KMS

https://technet.microsoft.com/en-gb/library/jj612867.aspx

https://grok.lsu.edu/Article.aspx?articleId=16651

https://saltwetbytes.wordpress.com/2012/07/30/resolving-a-product-key-not-found-error-on-a-ksm-client-on-windows-2008/