This is due to incomplete installation of an office...
You can check MS article click here for this issue.
You can search for the file for download on net.
You can have some registry modification, but before doing it, just back-up the registry keys.
Go into Registry Editor(Start->Run->Regedit)
Go to HKEY_LOCAL_MACHINE\Software\Microsoft\Office\11.0\Delivery.
There should be only 1 directory under Delivery, which is your DownloadCode (indicated by some numbers)
Select that directory [or all if more]. On the right side of the screen, right-click on CDCache. Change the value to 0 and the problem is solved