Until my significant other took over the second PC I had... then, I had to keep that system constantly in check. That system had numerous attacks of menu bars, installed programs, desktop programs, spy-ware, and registry attacks... With the amount of work I had to deal with, I located a nice "shareware" arsenol of programs to make the task easier; Spy-Bot for spy-ware and registry cleaning, and AVast for the many trojan and viri attacks. Failed attempts of "nailing down" Internet Explorer from accepting anything it receives from a web site, had me enabling AVast within IE, and daily running of Spy-Bot, just for the security issues, and for the uptime, we never saw more than a day of continuous running the systems, without having to do daily reboots. Firefox is holding back the cookies, and clamav is watching the viri attacks from the MS running emails we get, mostly spam, which, Spam Assassin is diligently throwing away as we receive them.
This sounds exactly like me at work, where this is exactly what I have to do to keep malware at bay using Windows at work. It is my end of day routine to scan for malware, etc. It takes 20 minutes -- everyday. Switching to Firefox Beta 2 has helped a lot. It's an ongoing BATTLE! We had to resort to configuring email for zero attachments. Then my boss got a different unpublished email account so vendors could send us graphics.

OTOH, at home, I NEVER have any problems like this. Linux has NO problems in these areas. Windows XP now behaves better because it is totally OFFLINE! Ha! Trouble is I rarely use it anymore.

sakiZ