You might keep in mind that Microsoft's Antispyware is a BETA software, meaning it is basically being tested by the public at large. There are groups of people who's only point in living is to find flaws in ANY Microsoft software. It takes 4, count them, 4 minutes for an unprotected computer on a broadband connection to become infected with Trojans, browser hijackers, spy-ware, and viruses. While this may sound like a typical Friday, or Saturday night in my boyhood home of Ninnecah, Oklahoma,or a New York Yankee fan Site, it will defiantly make life hard on you, and your computer. Zone Alarm is hands down the best software firewall out there for 2 reasons.
#1, it controls 100% access to, and from your computer to the net.
#2, it will notify in the event that you DO become infected with said Trojan, browser hijacker, spy ware, and-or virus that it is trying to access the net, and where it is located
AND WILL NOT LET IT HAVE ACCESS TO THE NET!
As far as spy ware protection, no 1 stand alone product on the market will protect you from the malware that is in circulation, or that is being developed as I rant now. I can personally recommend using in the following software to have a safe, and carefree web experience on the web

Zone Alarm-Software Firewall/Anti-Virus
PestPatrol-Anti Spyware
SpyBot Search and Destroy-Anti-Spyware
XP Antispy- xp-AntiSpy is a little utility that lets you disable some built-in update and authentication 'features' in WindowsXP
Notice ALL these products are Trial ware, meaning that they are free to evaluate for 2 weeks, to a month.
I would NEVER recommend buying ANY utility software until you try it first.
I'm not overly computer literate, I just built a few Holiday Inn Express's................