KMS Activate your Windows 8.1 installation
Step 1: Download KMSpico.exe from this link: KMSpico / Password: 2013
Step 2: Install KMSpico by disabling the Smartscreen on Windows 8.1
Step 3: Run KMSELDI and Autopico
Step 4: Make Tokens Backup
Step 5: Select the Volume License or Retail depending on the License status.
Step 6: Convert to Volume License if you are on a Retail version of Windows 8.1
Step 7: Activate Windows for 180 Days.
Proof of activation can be seen here: