solidworks not opening---WHY?

AS I try to open Solidworks now, i get a box saying: The filename, directory name, or volume labelsyntax is incorrect. Then I hit the "OK" button and I get this message: Could not open Solidworks DLL: slduiu.dll When I hit the "OK" button my solidworks screen disappears. Any idea what I need to do to get this working again? The last time using Solidworks it ran fine. Everything else works fine also. Thanks Dan Dix