[Today’s post comes to us courtesy of Vikramjit Singh and Mark Stanfill]


You may receive the following error after you add the 25-character alpha-numeric product key using the “Add Cal Pack Keys Wizard” on the EBS console Licensing tab.

Error Adding CAL.  The CAL product key entered is not valid for the operating system.

Error Adding CAL.  The CAL product key entered is not valid for this operating system.


The first thing to verify is that you bought the licenses (Standard/Premium) for the right product. We have seen a few instances where licenses were bought for Windows for Windows Essential Server 2008 (WinWess) and not Windows Essential Business Server 2008 (WEBS 2008)

Although similarly named, these 2 products are not interchangeable.


Windows for Windows Essential Server 2008 is a single server solution while Windows Essential Business Server 2008 is a 3 server solution (Management Server, Security Server and Messaging Server, with an optional 4th server for the Premium SKU). You cannot install Windows for Windows Essential Server 2008 licenses on Windows Essential Business Server 2008.


How can I verify that I have bought the right licenses?


Select the following link and download the document which includes all the SKUs for Windows Essential Business Server 2008 and Windows for Windows Essential Server 2008 and their respective licenses:


https://partner.microsoft.com/download/sverige/40086078

The definitive way to verify that you have acquired the correct SKU is to verify the part number from this document with your reseller.  EBS CALs are listed with a product name containing the string WinEssntlBsnssCALSte and have a part number starting with 6YA, while WinWess CALs contain the string WinSvrforWinEssntlSvr and have a part number starting with MYC.


If you have identified that the licenses purchased are for the wrong product, please contact your reseller/distributor and request for a replacement.