AppDefend is a kernel based application protection
system, designed to be secure whilst using few resources. AppDefend
intercepts various privileged actions and lets you decide whether
they should occur or not.
Without AppDefend you are highly vulnerable to rootkits, worms,
viruses and spyware. In some cases without AppDefend, the only
way to fix the problem would be to format your hard drive and
AppDefend is designed to work on Windows XP, 2000 and 2003.