The current version of the Office 2010 KMS Host License Pack cannot be installed on machines running Windows 8 or Windows Server 2012. Attempts to do so will result the error, "Unsupported operating system".
1/7/2013 UPDATE: The "Product activation failed" error that can occur when attempting to perform a phone activation of an Office 2010 KMS host installed on Windows 8 or Windows Server 2012 machines has been addressed in the latest release of the KeyManagementServiceHost*.exe file, which can be found in the link below.
12/4/2012 UPDATE: This issue has been addressed in the latest version of the Office 2010 KMS Host License Pack, which can be found at the link below.
Microsoft is working on an update for the Office 2010 KMS Host License Pack which will allow it to be successfully installed on Windows 8 or Windows Server 2012 machines.
All of the steps below are no longer required as of 1/7/2013. See related note above in red, bold text.
In the meantime, the following steps can be used to work around the issue:
1) Download the Office 2010 KMS Host License Pack (http://go.microsoft.com/fwlink/p/?LinkID=169244)
2) Run the downloaded KeyManagementServiceHost.exe file to extract files that it contains. Ignore the "Unsupported operating system" error that occurs and click OK.
3) Press the Enter key to close the command window that is related to cscript.exe.
3) Browse to the %programfiles% or %programfiles(x86)% folder and navigate to the MSECache\OfficeKMS subfolder. If you installed the Office 2010 KMS Host License Pack on a 64-bit operating system, %programfiles% is the Program Files (x86) folder.
4) Rename the existing kms_host.vbs file to kms_host.old
5) Download the kms_host.zip file from the Office Deployment Support Team's SkyDrive share at http://sdrv.ms/RiZ8Q9.
6) Extract the kms_host.vbs file from the zip file and place a copy of it in the %programfiles(x86)%\MSECache\OfficeKMS or %programfiles%\MSECache\OfficeKMS folder.
7) From an elevated command-prompt navigate to the %programfiles(x86)%\MSECache\OfficeKMS or %programfiles%\MSECache\OfficeKMS folder and run the following command:
7) If the KMS host machine has Internet connectivity, click Yes to enter the Office KMS host product key and activate online. Otherwise, click No, and press Enter to close the command window.
Open an elevated command prompt and run the following command line to check the installation, licensing state, and current status of the Office KMS host:
cscript slmgr.vbs /dlv bfe7a195-4f8f-4f0b-a622-cf13c7d16864
See the following articles for additional information related to Office KMS host installation, activation, and troubleshooting:
Deploy volume activation of Office 2010
Troubleshoot volume activation for Office 2010
Office Deployment Support Team Blog, "Office 2010 KMS installation and troubleshooting"