as a lot of people asked whether exchange 2007 sp2 can installed on windows 2008 r2 server, the answer is NO! ex pg said that exchange 2007 sp3 will support installed on a windows 2008 r2 server. Sp3 release date maybe is mid-June with a lot of product new versions.
how about ocs 2007 r2? Ok, it can installed on a windows 2007 r2 server but is not fully supported, like below scenarios is not supported:
- Office Communications Server 2007 R2, Group Chat will not function in a Windows 2008 R2 forest or when Group Chat member servers are joined to a Windows 2008 R2 domain. We know of an issue with changes in Windows 2008 R2 that requires a Group Chat Client and Group Chat Admin Tools hotfix. The Group Chat Client and Group Chat Admin Tools hotfixes are currently scheduled for mid-April 2010.
- Deploying Office Communications Server 2007 R2, Group Chat on the Windows 2008 R2 operating system is currently not supported.
- Upgrading the operating system to Windows Server 2008 R2 for an existing installation of Office Communications Server 2007 R2 is not supported.
- Office Communications Server 2007 R2 administration tools will only install in native 32-bit or native 64-bit mode. Because of an application compatibility issue with Windows Server 2008 R2, installing 32-bit Office Communications Server 2007 R2 administration tools on 64-bit Windows 2008 R2 operating system is not supported.
- Development with Speech Server (2007) Developer Edition and deployment of the Speech Server 2007 role are not supported on Windows Server 2008 R2.
you can get more information at http://support.microsoft.com/kb/982021