PowerPivot Installation error-"Could not load file or assembly 'Microsoft.AnalysisServices'"



Cause of the Error:

In SQL Server 2008 R2, the msmdsrv.exe process (which is the SSAS engine) includes a reference to the PowerPivot SharePoint integration dll (as do other components). Since the normal SSAS installation does not include the SharePoint integration dll, the registration marks the .NET assembly cache as failed. Later on, when you install PowerPivot, we copy the SharePoint integration dll to the right place, but the .NET assembly cache has already been marked failed from the previous SSAS installation and .NET does not attempt to load it (and you get the error message above).

Solution:

Workaround 

 

 References

 http://support.microsoft.com/kb/2261507