Before I post my question, I want to say ONE thing: this site's motto is "Hackers know the weaknesses in your system. Shouldn't you?" So, dont neg me for this post. Anywayz....

Here's the scenario:

Someone has my username to my XP box, but no password since I have not configured one. I have no remote services running, such as telnet, pop3, etc. How would penetration be possible? Remember, I have no "remote login" services, and a firewall. Dont tell me how to protect myself, just how would a hacker hack me? (no trojans involved)

Thanks, and no, this isnt for nefarious reasons.