I have installed Kaspersky Internet Security 7.0 on Vista, and it slowed my system to a crawl. It was probably Proactive Defence, but still. I could not stand it. I uninstalled it immediately. NOD32 is the only antivirus which claims to function with only 32MiB of RAM, though 64 is recommended. Yes, I have installed NOD32 2.7 Trial. Truthfully, I do not feel it. ESET claim that NOD32 is fast and uses low resources because it is written in assembler. Is the entire engine written in assembler, or only the critical parts? I do not believe that the GUI is written in assembler. It would not make sense. Also, is the firewall written in assembler as well? Right now, I'm using NOD32 2.7 with Windows Firewall. I have tried the Smart Security Suite before on XP. I'll probably try it again when Beta 2 is released. So far, my money is on ESET. PS: 2.7.0 claims that it's an antivirus only. Security Centre claims that no anti-spyware is installed and that I should and that I should enable Windows Defender.