Ever since my bro signed up for cable about a few weeks ago and set up the Netgear router w/ firewall, I was still skeptical, so I kept ZoneAlarm on my PC. There has been constant login attempts from my bro's PC, until today, when I found the log file empty. I left my computer on, took a nap for about 2.5 hours (two and a half

), then when I turned my monitor back on, I recieved a prompt by AVG that some trojan was detected and that I needed to scan to destroy it. Unfortunately, it didn't work, and I was finally forced, after 9 months, to reinstall Win XP Pro. Taking extra precaution, I left my computer unhooked the entire time I brought back in the OS, Office Suite, and other additive programs (ZA, AVG, etc.). Also, I noticed that one of my e-mail accounts matches the one on my PC account, so I changed that securely over another computer in my house. As a result, I don't think that anything of mine that is significant has been really exposed.
Then when I finally plugged the RJ-45 back in, there was still no logged firewall penetration attempt by my bro's PC, so after around 20 minutes, I turned it back off again.
So what do I do now? Although I've been downloading the Windows Updates constantly, I am assuming that the source of the problem is that whoever was trying to log in to my system finally found a new hole in my OS (I've been downloading pr0n from Kazaa, but I don't think that's the problem; BTW, as also extra precaution, I threw that all away, just in case

). So what do you guys think?