PowerPivot for SharePoint Installation

My first PowerPivot for SharePoint installation was done last year December, that was really far back where SQL Server 2008 R2 was still in CTP.

Last month, i have to setup the PowerPivot for my SharePoint 2010 RTM instance, in preparing for some demos and events.

My first attempt was really a smooth start, New Installation on Existing Farm brought me to the following screen, where i am happy to see that!

Now, my excitement does not last long when i start hitting some "Generic Error" that really cracking my head (First time, i did not capture the error log).

Went ahead and check out with my colleagues, we are suspecting the Claim to Windows Token Services was disabled, without second thought, we went ahead to enable the service, and restart the installation (No effect on my existing instance, thanks to Hyper-V snapshot).

Guess what, the installation is still failed! This time around, we are getting a different error message,

Could not load file or assembly 'Microsoft.AnalysisServices.SharePoint.Integration'.....or one of its dependencies. The system cannot find the file specified.

Arghh... what's wrong with my SharePoint, am i doing anything wrong? Man, what does it has to do with Analysis Services?

I am giving this up, and now is time to Bing around for answer, well, there are a few article out there that mentioned about the c2wts config, but what helped me was the article from PowerPivotGeek. (You guys ROCK!)

The explanation as following: -

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).

So i should be setting up at the following sequence?

1. Microsoft SQL Server 2008 R2 (Only Database Engine)

2. Microsoft SharePoint 2010

3. PowerPivot for SharePoint

4. Analysis Services and etc.

Is that correct? Anyone?