If you haven't updated your Vista to SP1 yet, here's something you might want to watch out for!

I had this happen on a machine that I just updated (finally) today.

After perforuming the update, I opened up SQL Server Management Studio, connected to my server instance and then tried to expand the Databases node.

I got this crazy error:

Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.VisualStudio.OLE.Interop.IServiceProvider'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{6D5140C1-7436-11CE-8034-00AA006009FA}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). (Microsoft.VisualStudio.OLE.Interop)

Happily, I found this blog post (thanks Antonio!) quickly enough which suggested two fixes - one to the registry itself and the other a quick re-registration of a particular dll. I chose the latter (less impact on my system) and the problem went away instantly.

C:\WINDOWS\system32>regsvr32 actxprxy.dll

It did take a few tries with the proper search term to find the exact scenario, since that error does come up in a variety of situations, which is why I thought I would highlight it here.