I'm very glad a co-worker told me about Microsoft Security Essentials!
Why? Primarily so that the notifications center will stop telling me that my Windows setup is insecure. I consider Windows to be an inherently insecure product, and while I find it affirming that Windows itself agrees with me, I find it obnoxious for it to keep alerting me of this fact, and somehow trying to pin the blame on me, the user.
Back to Microsoft Security Essentials - its available at for no fee from the Microsoft website: