Problem: ArcToolbox tools do not start when double-clicked
When ArcToolbox tools are double-clicked, nothing happens or a brief hourglass appears.
Microsoft XML parser 3.0 Service Pack 4 (SP4) or XML Core Services 4.0 are not installed or have been removed since the installation of ArcGIS 9. This prevents the dialogs from being generated or displayed.
Solution or Workaround
Install the Microsoft XML Parser 3.0 SP4 and XML Core Services 4.0 from the links in the Related Information section below.
Even if the XML parser 3.0 and XML Core Services appear to be installed, rerun the install for both of these components; this will replace any files that may be missing or corrupt.