There are a couple of new security threats out for Microsoft Windows and Internet Explorer. The primary one of concern is this one:

Basically, if you click on a malicious website, that website could run any software it wants on your computer and take it over. The reason for this warning is that there is proof of concept code out already, and that means that it is more likely that someone may actually develop a >malicious program (virus/trojan) to try and take advantage of this.

Currently, there is not a patch for this. It is possible to disable activeX in Internet Explorer, but this will also disable a lot of functionality you may be used to.

The best protection is to not open any web links in emails sent to you, and avoid visiting websites you do not trust.

As of now, Microsoft plans to wait till April 11th before releasing a patch for this. If we are lucky, maybe they will release it earlier.