Unable to load the vertipaq engine because there was a COM exception . Return argument has an invalid type.

Question

Hi All,
I have been using powerpivot for months (2010 PowerPivot on Excel 2010, with Sql 2008).  I tried to open powerpivot today and get the following below.  I have already tried uninstalling powerpivot and reinstalling it to no avail.  
Any suggestions would be appreciated.  Thanks, Ivan
Unable to load the vertipaq engine because there was a COM exception while loading....
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Error Message:
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Return argument has an invalid type.
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Call Stack:
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   at System.Runtime.Remoting.Proxies.RealProxy.ValidateReturnArg(Object arg, Type paramType)
   at System.Runtime.Remoting.Proxies.RealProxy.PropagateOutParameters(IMessage msg, Object[] outArgs, Object returnValue)
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at Microsoft.Office.Interop.Excel.WorkbookConnection.get_OLEDBConnection()
   at Microsoft.AnalysisServices.XLHost.Addin.InProcServer.LoadOLEDBConnection(Boolean raiseCompleteEvent, String errorCache)
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Answer 1

Hi All,
For anyone who this happens to, what ended up fixing it was uninstalling and reinstalling excel.  I was using excel 2010, so I did this 
Go to add/remove programs 
Highlight Microsoft Office Professional 2010 
Click Change
ensure Add remove features is selected and click continue 
click on the little arrow beside excel and click on Not Available, click continue
After it is done, excel will be uninstalled.  
When this is done, you can do the same process again, but this time chose the other appropriate selection
instead of not available.  I chose Run All from My Computer.