Microsoft has posted the online documentation for the KMS keys for their latest OSes. The KMS keys we’ll be most interested in are these:
- Windows Server 2012 R2 Standard (for most server installs): D2N9P-3P6X9-2R39C-7RTCD-MDVJX
- Windows Server 2012 R2 Datacenter (for Hyper-V server installs): W3GGN-FT8W3-Y4M27-J84CP-Q3VJ9
- Windows 8.1 Enterprise: MHF9N-XY6XB-WVXMC-BTDCT-MKKG7
The two Server 2012 R2 editions are identical except for the number of VMs that are licensed per host. The Standard edition is licensed for only two VMs (but can essentially be extended by consuming additional licenses…which we have a site license for, so effectively unlimited). The Datacenter edition, however, starts at unlimited VM licensing, so we are recommending that for Hyper-V servers and the Standard edition everywhere else.