Microsoft released their beta AntiSpyware software today. Many rumors are floating about that they will start charging for this software in the near future. Check out their AntiSpyware FAQ and you'll see their answers hint that they will eventually charge you for the full release. (see questions "How much does Windows AntiSpyware (Beta) cost?" and "Do I need to register Windows AntiSpyware (Beta)?") Should you use it? Well, let's see...
Pros.
Cons.
My vote? Not yet. Get more information on protecting your computer.