Some settings that control ArcMap operations are not accessible through the interface. The Advanced ArcMap Settings tool provides a way to adjust some of those settings.
Run SetupArcGIS.exe from the install location.
Expand the ArcObjects Developers Kit feature.
Set the Utilities option to 'Will be installed on local hard drive' and click Next.
Click Next again to install the utilities.
After the install completes, navigate to Utilities:
For ArcGIS 8.1, from the ArcGIS folder, click Arcexe81\ArcObjects Developer Kit\Utilities\VBAdvancedSettingsUtility.
For ArcGIS versions 8.1.2 and higher, click \arcgis\arcexe\utilities.
Double-click the AdvAMSet.exe file to start the tool.
For more information about what the Advanced Settings Utility does, refer to the MS Word document called "ArcMap Advanced Settings Registry Keys. doc" that accomapanies the utility. It is found in the same directory as the utility.