I was running only norton antivirus 2003 professional. I suddenly woken up at 02:53am because my pc was restarting. My comptuer was vulnerable because even though i knew a worm was hanging around on the net, i couldn't install the MS patch because i didnt know how to install it in xpsp2. (Otherwise i would have no problem).
Couldn't do anything that morning (weekday) and as soon as i came home from work, i disbled msblast.exe from the msconfig > startup.
Now i got norton personall filewall installed. I still havent restarted the pc to manually install the ms patch.
The computer still gets infected by the worm as soon as the firewall is turned off, and i am just surviving by "shutdown -a" thanks to Sephiroth.
I know my computer is still vulnerable.