We have purchased Datcenter 2008 processor licenses for the purposes of running unlimited Windows guest servers on an ESX cluster.The product keys available to us through eOpen are KMS and MAK. As we won't be running physical Windows servers, we believe we will need to use MAK licensing.Now, Datacenter 2008 licensing entitles us to run DC, Enterprise or Standard guests, and downgrade rights entitles us to run 2003 DC, Ent or standard guests.Our question is - how do we obtain product keys for each of these guest types? We have tested the Datacenter 2008 MAK against a Enterprise 2008 build and the key doesn't work - states it is for use with Datacenter only.Any advice appreciated,Peter

Hello,check this page about getting the correct key for your licensing option:http://www.microsoft.com/windowsserver2008/en/us/downgrade-rights.aspxBest regards Meinolf Weber Disclaimer: This posting is provided "AS IS" with no warranties, and confers no rights.

Hi Meinolf, the link provided "the key" we were looking for:"If you already have media and product activation keys for the earlier version of the product that you have downgrade rights to, you can use that media and keys to downgrade to an earlier version."Many thanks,Peter