Reading headlines of MVP blogs can be really interesting… reading the content of the article can also be very helpful ;). Sean Wallbridge writes that Exchange 2007 is not supported on Windows Server 2008 R2.
At the end of his article he mentions possible Server 2008 upgrade issues with SharePoint 2007.
Exchange 2007 not supported on Windows Server 2008 R2
It is written at the Exchange Team Blog that this configuration is not supported. You can read more at Sean Wallbridges blog Heads Up – Exchange 2007 cannot be installed on Windows Server 2008 R2 (Note “R2”).
References:
SharePoint 2007 and Windows Server 2008 upgrade to R2
When you receive the following error message:
Error message when you upgrade Windows Server 2008 to Windows Server 2008 R2: "These Windows features might not work properly after the upgrade"
it’s time to update your SharePoint installation!? Although KB 962216 suggest uninstalling WSS 3.0 before you upgrade Windows Server 2008 to R2 I know that sometimes it’s not possible to uninstall WSS 3.0 if you need it in production.
So what to do? And what about impacts on MOSS 2007? I don’t know but you should update your farm to SP2 since SharePoint 2007 without SP1 is not supported.
So I guess Windows Server 2008 upgrade with SharePoint 2007 SP2 is fine…
Update 29. August 2009
You can’t upgrade Windows Server 2008 to Windows Server 2008 R2 if you have installed Microsoft Office SharePoint Server 2007 without Service Pack 2. You can refer to KB962935: “You cannot upgrade from Windows Server 2008 to Windows Server 2008 R2 after you install Office SharePoint Server 2007 on a computer that is running Windows Server 2008”.
The article isn’t available yet so there is no link. The error message is something like that:
These Windows features might not work properly after the upgrade. We recommend turning off features before upgrading. Cancel the upgrade, open Control Panel and search for "turn Windows features on or off".
Microsoft Office SharePoint Server 2007