Vote for OverflowGuard
OverflowGuard for Windows NT / 2000 / XP / 2003 protects Microsoft programs from known and unknown buffer overflow exploits. Traditionally the only way to protect your Windows system against buffer overflows was to install a patch from the vendor after the vulnerability was known. This left a period of time when hackers could break into your system regardless of how quickly you installed vendor patches. Buffer overflow exploits are a favorite way for hackers to break into systems. Worms such as MS.Blaster and CodeRed rely on these bugs to spread. Two versions of OverflowGuard are available, one protects almost every Microsoft service on the system and the other protects only Internet Explorer, Outlook Express and Outlook.