Windows Worms Doors Cleaner is a handy utility to close unsafe and known vulnerable aspects of Windows, like services and ports.
Windows, being the most widely used operating system, also happens to have tons of known vulnerabilities. Microsoft usually fixes them by pushing out updates, but there are known vulnerabilities, information being widely available on the web. Many popular and destructive worms use vulnerabilities in Windows services. They also disable registry editing, so fixing them would be a pain.
This is where Windows Worms Doors Cleaner comes in: it disables vulnerable services and processes, checks process names with lists of known worms and monitors svchost.exe memory usage levels.
The user interface for Windows Worms Doors Cleaner is relatively good, providing you information about what services and ports are disabled, a button to re-enable them and a link to the official Microsoft security bulletin.
When it finds that something is to be disabled, it modifies existing registry entries instead of creating new ones, so you do not have to worry about a bloated registry after using it for some time.