thanks, Rick~!
*Relieved*
Yeah I thought the host file's only purpose is to map a string to an ip, but i didn't know that it can block traffic (Actually I did it before, I screwed one of the comp in my school with the hosts file, but then, it was last year and I forgot about it)
I originally thought it was IIS' fault, then I thought a virus/trojan might had slipped through my NAV, until my friend suspected that it's something to do with the network.
So far, very good. My port 80 is no longer being flooded.