Microsoft Outlook error missing a dll file

Hi there,
This morning Microsoft Outlook showed up this error message box. Is for the first time when I have this kind of error, actually I never had errors with Outlook. I tried to reinstall and is not working. Please is there a solution for this error? How can this be solved?
Thank you!

Microsoft Outlook
The add-in “C:WINNTSystem32ActExt.dll” could not be installed or loaded. This problem may be resolved by using Detect and Repair on the Help menu. Unable to load C:WINNTSystem32ActExt.dll. You may be out of memory, out of system resources, or missing a dll file.
OK
