HP Compaq nc6400 Notebook Update and HP Software Update - Critical Security Update v1.00 C for Windows Vista 64-bit/32-bit/XP/2000 [b]Operating System(s):[/b] Microsoft Windows 2000, Microsoft Windows Vista Business (32-bit), Microsoft Windows Vista Business (64-bit), Microsoft Windows Vista Enterprise (32-bit), Microsoft Windows Vista Enterprise (64-bit), Microsoft Windows Vista Home Basic (32-bit), Microsoft Windows XP Home Edition, Microsoft Windows XP ProfessionalThis package provides an HP Update and HP Software Update - critical security update for the supported notebook models and operating systems. This security update applies a registry modification to address a potential security vulnerability with the HP Software Update.