Product Version       = Sun ONE Studio, Native Edition
 (Build 030722)-- build 14                  
IDE Versioning        = IDE/1 spec=3.42.1 impl=030722
Operating System      = SunOS version 5.8 
Java; VM; Vendor = 1.4.1_02; Java
HotSpot(TM)Client VM 1.4.1_02-b06; Sun
Microsystems Inc.

1.Tools->Options->IDE Configuration->Server and
External Tools Settings->Diff Settings
2.Select 'Default Diff Engine' property editor
3.Wait for the 'Default Diff Engine' dialog

See results of Accessibility Tester:
===============================================
 Tested Window title : Default Diff Engine
===============================================
 No Accessible name :
   Class:
org.openide.explorer.view.TreeView$ExplorerTree {
 |  } 

 No Accessible description :
   Class:
org.openide.explorer.view.TreeView$ExplorerTree {
 |  } 

 Components with no LABEL_FOR pointing to it :
   Class:
org.openide.explorer.view.TreeView$ExplorerTree {
 |  }