This was Comodo’s "killer feature." Since XP is vulnerable to memory exploits and buffer overflows, traditional antivirus definitions often fail. HIPS works differently; it monitors the behavior of files. If an unknown executable tries to modify the registry, access the keyboard, or inject code into another process, Comodo blocks it and alerts the user. For an unpatched XP system, this proactive defense is vital.
Unlike the native XP firewall, Comodo tracks both incoming and outgoing connections, preventing "phone-home" malware from stealing your data. comodo firewall xp