Is it possible, or do I have to trash my beta 3 VM and create a fresh June CTP one, please? Many thanks, Marc

Yes, option to upgrade from beta 3 is available. No need to trash your beta 3 vm.

From the download page: The SQL Server 2008 June CTP has known compatibility issueswith Windows Vista and Windows Server 2008 Beta.We do not recommend testing this CTP on this configuration. So, do we need a clean box to test it?

Hello Mark (with the k),I think Marc and Acchong are talking about upgrading Windows itself, which is possible for MSDN and TechNet subscribers :from Longhorn beta 3 to Windows Server 2008 IDS-3 CTP build: 6001.16606.070619.0730 (see here)You probably mean: SQL Server 2008 Katmai with the Windows Server 2008 (Longhorn) beta 3 ?I have this info: "...CTP3 is not supported on Vista. We will not be adding support for Vista or LH until CTP5." (see here)Sincerely,Erkan YILMAZ