When restarting the computer after a windows download, I get to my wallpaper but no icons or task bar.  The message displayed says:

 

Explorer.exe unable to locate component.  This application failed to start because SHDOCVW.dll was not found.  Re-installing the application may fix the problem.

 

Could somebody please help?  And don't tell me to go to the START menu, since obviously I don' have one on my screen.  :-)