I'll be honest, you probably shouldn't be using Microsoft's built in security suite. It's not that good. If you are connected to the net via a router it'll have a firewall built in that will be miles ahead of the software one that Microsoft windows comes with, but you can still use that if you like. For Anti-virus though you should use Avast!, because it's completely free and is actually really good. There's also AVG if you prefer.
As for Spyware detection and removal, you should use these program: Spybot: Search and Destroy and Spyware Blaster.
The first will detect and remove problems on your PC, the second will patch any security holes in your computer that Windows Update missed.
Always remember to keep your microsoft windows updated fully, because that'll stop a lot of things getting through too.
There we go. Entirely free security suite.

As for Chrome, I doubt it's microsoft being evil. It was probably something getting through the windows security systems and infecting Chrome. As I said, Windows Security isn't so hot. Hence my suggestions.
Happy computing.