Cannot activate Windows 2012r2 Standard

Running cmd.exe as Administrator:

Slmgr.vbs /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
-->> it gives error: 
Windows Script Host
Error: 0x8007041D On a computer running Microsoft Windows non-core edition, 
run 'slui.exe 0x2a 0x8007041D' to display the error text. 

and:

slui.exe 0x2a 0x8007041D
-->> 
Windows Activation
An error has occured
You can also contact Microsoft by phone to help resolve
this problem. 
Code: 
0x8007031D

Description: 
The service did not respond to the start or control request in a timely fashion. 

Telnet is not installed. Cannot install it via Windows Features, gives error, maybe because it isn't activated.

Question: What is this activation error?

If I try with the:

Slmgr.vbs /skms kms_server:1688

I got the same error message, maybe a client-side problem?

Open up an elevated cmd prompt and enter the following commands to uninstall and reinstall the Product Key:

slmgr –upk 
slmgr –cpky
slmgr –rilc
slmgr –ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
slmgr –ato

NOTE: Useful commands for SLMGR

-dli -> Display License information

-dly -> Display detailed License Information

-upk -> Uninstall Product key

-ipk $key -> Install Product Key

-ato -> Activate Windows

-rearm -> Reset the Licensing Status of the machine

-cpky -> Clear product key from the registry

-rilc -> Reinstall System License Files

Also, you can open Server Manager -> Local Server -> Click your Product ID and Windows Activation prompt will popup.

However, if you plan to use volume activation, please refer to:

Volume Activation Overview for Windows 8 and Windows Server 2012

http://technet.microsoft.com/en-us/library/hh831612.aspx

Appendix A: KMS Client Setup Keys

http://technet.microsoft.com/en-us/library/jj612867.aspx

If you run Evaluation Versions, please refer to Evaluation Versions and Upgrade Options for Windows Server 2012.

Source 1 and Source 2