The Arctoolbox dialog boxes do not display on the screen, however, they do appear to show up on the taskbar.
Note: The content in this article pertains to ArcGIS versions 8.x and 9.x. Later versions of ArcGIS may contain different functionality, as well as different names and locations for menus, commands and geoprocessing tools.
The window position in the Registry has incorrect or negative values.
Note: Before following any of the procedures below, connect a second monitor and reconfigure the Display Settings in Windows by extending the main display. If the dialog box is visible in the extended display area, drag it to the primary monitor. Close and restart ArcMap. If the dialog box is still not visible, try adjusting screen resolution. If the dialog box is visible, drag it to the primary monitor. Close and restart ArcMap.
Change the window position of the dialog box in the Registry.
Warning: The instructions below include making changes to essential parts of your operating system. It is recommended that you backup your operating system and files, including the registry, before proceeding. Consult a qualified computer systems professional, if necessary. Esri cannot guarantee results from incorrect modifications while following these instructions. Therefore, use caution and proceed at your own risk.
Note: In some 10.x versions of ArcGIS Desktop, a problem has been identified where the new Registry settings are not maintained. This has been logged as BUG-000115257 . If this is the case, the following workaround is offered, however with some caveats.
Warning: The following workaround may have unintended results. Renaming the Normal.mxt template may remove any ArcMap customization, such as activated toolbars, toolbar/panel positioning, and folder/database connections.
For more information about the Normal.mxt file, read the following web help document, Fundamentals of saving your customizations.