Some day's ago microsoft Releases exchange 2010 SP1. When you install Exchange 2010 SP1 you need to install some hotfixes. The Exchange Team have made a nice over view witch hotfixes you need for the OS.
|windows Server 2008
|Windows Server 2008 r2
|windows 7 & Windows vista
A .NET Framework 2.0-based Multi-AppDomain application stops responding when you run the application
or Microsoft Connect
|Windows6.0-KB979744-x64.msu (CBS: Vista/Win2K8)
|Windows6.1-KB979744-x64.msu (CBS: Win7/Win2K8 R2)
An ASP.NET 2.0 hotfix rollup package is available for Windows 7 and for Windows server 2008 r2
|Request from CSS
AD RMS clients do not authenticate federated identity providers in Windows Server 2008 or in Windows Vista. Without this update, Active Directory Rights Management Services (AD RMS) features may stop working
|Request from CSS using the “View and request hotfix downloads” link in the KBA | US-English
|Select the download for Windows Vista for the x64 platform.
Two issues occur when you deploy an ASP.NET 2.0-based application on a server that is running iis 7.0 or IIS 7.5 in Integrated mode
|Request from CSS using the Hotfix Request Web Submission Form or by phone (no charge)
FIX: ArgumentNullException exception error message when a .NET Framework 2.0 SP2-based application tries to process a response with zero-length content to an asynchronous ASP.NET Web service request: “Value cannot be null”.
rpc over HTTP clients cannot connect to the Windows Server 2008 rpc over http servers that have RPC load balancing enabled.
|Request from CSS
|Select the download for Windows Vista (x64)
An update is available to remove the application manifest expiry feature from AD RMS clients.
WCF services that are hosted by computers together with a NLB fail in .NET Framework 3.5 SP1
|X86: Windows6.1-KB982867-v2-x86.msu (Win7)
x64: Windows6.1-KB982867-v2-x64.msu (Win7)
FIX: An application that is based on the Microsoft .NET Framework 2.0 service pack 2 and that invokes a Web service call asynchronously throws an exception on a computer that is running Windows 7.
Some of the hotfixes would have been rolled up in a Windows update or service pack. Given that the Exchange team released SP1 earlier than what was planned and announced earlier, it did not align with some of the work with the Windows platform. As a result, some hotfixes are available from MSDN/Connect, and some require that you request them online using the links in the corresponding KBs. All these updates may become available on the Download Center, and also through Windows Update.
These hotfixes have been tested extensively as part of Exchange 2010 SP1 deployments within Microsoft and by our TAP customers. They are fully supported by Microsoft.
You can use the Install the Windows Server 2008 SP2 operating system prerequisites on a windows 2008 r2 server. Only you have to run the following powershell command: Import-Module ServerManager
Installed Exchange 2010 SP1 on a Windows 2008 R2 Server with problems. I feels that the MMC is faster. Tomorrow upgrading a DAG/NLB cluster to Exchange 2010 SP1.