They all have limitations
Ok, so the good news is that Microsoft's Anitspyware programs (BETA) really does work. Its the best thing since sliced bread in the computer industry. This is because Bill Gates and company can't be bought out by webmasters designing spyware.
The bad news is that it is Microsoft.
Spyware simply put is the reaction to a growing demand. Webmasters and companies (usually porn or gambling sites) want to generate dollars, by plying on our vices. You can't get spyware if you follow the basics.
1. Use a good antivirus program religously.
2. Never ever accept cookies randomly, it's like playing russian roulette.
3. If the web offer looks to good to be true it usually is. Spybot, Spyhunter, Spysweeper and all the other "freeware" verisons of this type have one fatal flaw - They attract spyware. Companies and webmasters pay the developers to "ignor" their spy software. Sad but true.
Load Microsoft, pay for it when it leaves BETA testing and be gratefull that some people can't be bought.