Interesting. In a world of popups, spyware, malware, etc., it looks like Microsoft is trying to enter this space with their own proudct. I'm sure it will remain free and I'm sure that MSFT needs to do stuff like this to keep their customers happy. With so many third party companies out there making software from A to Z, Microsoft seems a bit slow on this. Then again, they don't have their own antivirus software. Strange. I wonder why?
BE WARNED!!! You apparently need to validate your copy of Windows before downloading this. There is an option to NOT VALIDATE, but I'm not sure how this all works out.
Try the beta anti spyware software.
Ars Technica's Article on It