Problem:
You get the following error when trying to browse SQL Server with the Object Explorer in MS SQL Server Management Studio:
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)).
Solution:
There are many possible solutions to this problem.
The first thing to try is to unregister and then re-register two dll's and then reboot.
1. Re-register ieproxy.dll:
regsvr32 /u "C:\program files\internet explorer\ieproxy.dll"
regsvr32 "C:\program files\internet explorer\ieproxy.dll"
For windows 7 Replace the 2 lines above with the following 2 lines.
regsvr32 /u "C:\program files (x86)\internet explorer\ieproxy.dll"
regsvr32 "C:\program files (x86)\internet explorer\ieproxy.dll"
2. Re-register actxprxy.dll:
regsvr32 /u "C:\windows\system32\actxprxy.dll"
regsvr32 "C:\windows\system32\actxprxy.dll"
3. Reboot your computer.
If this doesn't solve the problem, here are a few useful links.
http://social.msdn.microsoft.com/Forums/en-US/sqltools/thread/d5d3e5fc-d8ce-4f42-b7ea-9bbbb7756a20
http://support.sourcegear.com/viewtopic.php?f=5&t=12680&p=52790&hilit=management+studio#p52790
http://www.davidmoore.info/2009/08/19/solution-explorer-open-each-folder-in-same-window-error-and-sql-management-studio-ie-and-team-explorer-errors/