Check out this <a href="http://www.microsoft.com/Sqlserver/2005/en/us/special-considerations.aspx">http://www.microsoft.com/Sqlserver/2005/en/us/special-considerations.aspx</a> If depends. If you have SQL Server Enterprise Edition installed, then you can buy enough CPU licenses to cover the host and all VMs on that host will be covered. If you have Standard Edition you need to license each VM by it self. So if you have a 4 CPU server, and you have Enterprise Edition, you can purchase 4 CPU licenses of SQL Enterprise and you are covered for all SQL Instances you install on that piece of harddware. However if you have standard edition, and you have 2 VMs running SQL Server with 4 vCPUs each, then you need to purcahse 8 standard edition licenses. Hopefully that helps.

Check out this <a href="http://www.microsoft.com/Sqlserver/2005/en/us/special-considerations.aspx">http://www.microsoft.com/Sqlserver/2005/en/us/special-considerations.aspx</a> If depends. If you have SQL Server Enterprise Edition installed, then you can buy enough CPU licenses to cover the host and all VMs on that host will be covered. If you have Standard Edition you need to license each VM by it self. So if you have a 4 CPU server, and you have Enterprise Edition, you can purchase 4 CPU licenses of SQL Enterprise and you are covered for all SQL Instances you install on that piece of harddware. However if you have standard edition, and you have 2 VMs running SQL Server with 4 vCPUs each, then you need to purcahse 8 standard edition licenses. Hopefully that helps.