[discostu]

This has nothing to do with the OS. Any software package could install extra stuff you're not seeing regardless of your OS. Spyware comes in all flavors. And the best anti-spyware is free anyway.

[N3WBI3]

Really? at the system registry level? Linux and Mac prevent user accounts from mucking around with the global libraries.. In addition they come *with* a firewall, you dont need to install third party software to get one..