Can't be done as far as I know. Even if you make a system backup and install Server 2008 Std. and try to restore from the system backup you will have enterprise.
EDIT I could not fully test it yet, but it does allow at least to pass the previous warning message that "Can not upgrade..." etc Will keep you posted.... sebus
Renaming "Windows Server 2008 R2 Enterprise" to "Windows Server 2008 R2 Standard" and "ServerEnterprise" to "ServerStandard", and doing an in-place upgrade, moves R2 Enterprise to R2 Standard successfully (at least using VL edition and without any product key entered).
Hi Unfortunately this does not work, I have done everything you have said,changing the registry keys, I rebooted the server, but when i try and upgrade i get the message saying that The current version installed is newer than the version you are trying to upgrade to, the upgrade will not proceed. I am trying to go from server 2008 Enterprise back to server 2008R2 standard. just for yoru information, this server did start out as server 2008R2, i used this method to upgrade to enterprise as I needed to see more memory, but plans have now changed and i need to go back to server 2008 r2 standard any advice would be appreciated Thanks
Did you check if the reg mod was still there after the reboot? Anyway reboot isn't needed, just try to "upgrade" straight after the reg mod.