GFI LANguard System Integrity Monitor 3.0Free
GFI LANguard System Integrity Monitor (S.I.M.) is a utility that provides intrusion detection by checking whether files have been changed, added or deleted on a Windows 2000/XP system. If this happens, it alerts the administrator by email. Because hackers need to change certain system files to gain access, this FREEWARE utility provides a great means to identify any servers that are open to attack.