Windows 8.1 and Windows Server 2012 R2 Client Setup Keys

Operating system edition	KMS Client Setup Key
Windows 8.1 Professional	GCRJD-8NW9H-F2CDX-CCM8D-9D6T9
Windows 8.1 Professional N	HMCNV-VVBFX-7HMBH-CTY9B-B4FXY
Windows 8.1 Enterprise	MHF9N-XY6XB-WVXMC-BTDCT-MKKG7
Windows 8.1 Enterprise N	TT4HM-HN7YT-62K67-RGRQJ-JFFXW
Windows Server 2012 R2 Server Standard	D2N9P-3P6X9-2R39C-7RTCD-MDVJX
Windows Server 2012 R2 Datacenter	W3GGN-FT8W3-Y4M27-J84CP-Q3VJ9
Windows Server 2012 R2 Essentials	KNC87-3J2TX-XB4WP-VCPJV-M4FWM

To install a client setup key, open an administrative command prompt on the client, type slmgr /ipk  and press ENTER.