Andrea --
This indicates that the Windows Script system (part of the Windows OS) is not working right. MUI means "Multilingual User Interface". I don't know how to diagnose your specific situation, but I did find what seems like a good Microsoft article on this:
http://technet.microsoft.com/en-us/l...87(WS.10).aspx
at the bottom of this long article is a posted comment with a download link for language packs:
http://www.microsoft.com/unlimitedpo...grams/llp.mspx
Perhaps this will help finding what is missing of partially installed on that system.