How to activate a Windows Server 2012 R2 key?

Redeeming a Windows Server 2012 R2 key is really simple, just follow these steps:

1. Download Windows Server HERE,
2. Change Evaluation to Regular.

• For Windows Server Datacenter, please use the following command:
  DISM /Online /Set-Edition:ServerDatacenter /ProductKey:XXXX-XXXX-XXXXX-XXXXX-XXXXX /AcceptEULA 
• For Windows Server Standard / Essentials, use this command:
  DISM /Online /Set-Edition:ServerStandard /ProductKey:XXXX-XXXX-XXXXX-XXXXX-XXXXX /AcceptEULA 

3. Proceed with activation.

The key is not working

If you have activated the key according to the guide but the code appears not to work, please check what type of error message you receive and depending on it follow the appropriate instructions:

• My key is Duplicated / Already used
• My key is Invalid
• My key is region locked / can't be activated in my country
• My key activated a different product
• My key did not activate all of the content