Activating Windows 8 Enterprise

If you use Windows 8 Enterprise without a KMS server, you may have been unable to activate it.

Windows 8 Enterprise activation error without a KMS server

The Windows 8 Enterprise edition assumes an environment with a KMS server and searches for it through the SRV record _vlmcs in DNS, resulting in this error:

Message: DNS name does not exist

Without a KMS server, first change the product key to your actual key.

Activating Windows by changing the product key

Another change in Windows 8 Enterprise is that the product key cannot be changed as in Windows 7 Enterprise. Fortunately, only the GUI lacks this option; use the SLMGR tool.

Changing the product key with SLMGR

Run a command prompt (CMD) with administrator rights
enter:
slmgr /ipk "Váš Product Key"

"Your Product Key", entered without quotation marks

More at: https://technet.microsoft.com/cs-cz/library/dn502540.aspx?f=255&MSPPError=-2147217396