How do I – Uninstall PowerPivot for SharePoint 2010

Given how much effort is was to get PowerPivot installed and working in the first place, you may never need this post, but just in case something goes wrong and you have to uninstall it to start over, here’s how to do that:

1. Launch Programs and Features via Start/Control Panel/Uninstall a Program.
   
2. Locate the “Microsoft SQL Server 2008 R2 (64-bit)” entry and select it with a left click.
3. The Uninstall/Change button becomes active.  Click it.
   
4. Windows may warn you that there are other users that’ll be affected.
5. Click “Continue” to ignore the warning and proceed.
   
6. The SQL Server configuration tool opens.
7. Click “Remove”.
   
8. Setup will load all the support rules.
9. Once all rules were loaded, click “OK”.
   
10. Change the “Instance to remove feature from” dropdown value to “POWERPIVOT”.
11. Click “Next”.
    
12. Ensure that “Analysis Services” and it’s sub categories under POWERPIVOT is checked.
13. Click “Next”.
    
14. Setup runs all the removal rules.
15. Once the rules have run successfully, click “Next”.
    
16. On the Ready to Remove screen, click “Remove”.
    
17. Once setup has removed PowerPivot, you’ll be taken to the Complete screen.
18. The status should indicate that the removal was successful.
19. Click “Close”.
    
TROUBLE SHOOTING TIP
If you have previously removed PowerPivot and am trying to reinstall it again, the installation may fail because the removal didn’t cleanup everything properly.
If you install PowerPivot and go to the Solution administration page, there’s a .wsp for PowerPivot called “powerpivotfarm.wsp”.  If this solution shows an error with a message of “Some of the files failed to copy during deployment of the solution”, then the uninstaller didn’t cleanup everything successfully.

Looking at the error above, the Microsoft.AnalysisServices.SharePoint.Integration.dll assembly didn’t get deployed to the GAC.
If you browse to the GAC via Windows Explorer, you’ll see this:

OK, so it is NOT there.  That’s what we expected because that’s what the error indicated.
Ah… but wait… there’s more…
Open a command prompt on the server.
Now manually change directory to the GAC_MSIL folder and do it dir for that DLL.
And what do we get?…

It seems that the folder was not cleaned up successfully during a past uninstall.  The installer isn’t smart enough to figure out that’s the right folder to put the DLL and simply throws an error.  It wants to create the folder from scratch.
Us the RD command to remove the offending folder and then retry your installation.  Odds are it’ll work this time.


Cheers
C