Hi,
I understand that you don't actually download the Adventure Works SSAS database. You build the Adventure Works SSAS database by deploying the Adventure Works BIDS / SSAS solution using the Adventure Works .MDF as a data source.
Can you find a folder called "AdventureWorks 2008R2 Analysis Services Project". If so open up the solution within this folder and deploy.
Also have a look at the following link; -
http://msftdbprodsamples.codeplex.com/wikipage?title=Installing%20Analysis%20Services%20Database
Kind Regards,
Kieran.
If you have found any of my posts helpful then please vote them as helpful. Kieran Patrick Wood MCTS BI, PGD SoftDev (Open), MBCS, MCC http://uk.linkedin.com/in/kieranpatrickwood