No Defense Against Windows Rootkits?

An anonymous reader writes "Spyware bad guys (and also phishing people) started using rootkits technology to stay hidden in a system. The problem is that at the moment the technology to defend a Windows system from these things is very poor. In fact antivirus companies have just started adding basic anti-rootkits technology. So the problem is serious, and well outlined by this question: Is the closed source code of Windows preventing us from actively defending our systems?"