My computers are all fine with enough apps running to fill 3 taskbar rows… I think at one point I counted over 50 application instances on my 2.1ghz laptop. That wasn’t including the extra background processes running in the icon section of the taskbar.
Well that’s what Vista’s security model tries to address… however, since windows developers have always written software presuming you have administrator access, it seems that the “you need to be admin” prompting got to be way too much for everyone using Vista… so, everyone turns that feature off. Once Windows developers start realizing that it’s important to use the new security model, it will become much more user friendly to be secure… just like in Linux 
What vista really needs is an “always run this application as admin” option, for those pesky apps that will never be updated.
)but i have had windows with norton antivirus for a few years now,and my comp is fine…
And it was back in the days with Windows 95 and no antivirus software whatsoever. It’s just a matter of being careful what sites you visit and what software you let on your machine. And, perhaps most important of all, avoiding Internet Explorer like hell.