I will go farther ... it is IRRESPONSIBLE and a disservice to the Internet community to continue to run a known-insecure distribution of ANY OS directly facing the Internet. Which is why I STRONGLY urge my clients, friends & family to put their vulnerable Windoze boxes behind hardware firewalls (=cheap, off-the-shelf routers) if they have broadband, and at the very least to use XP's built-in firewall or another software firewall on their dialup connections.
One fellow I know connected his XP box to a dialup for *three minutes* ... it had been happy and content behind a broadband firewall before he took it on the road ... and within three minutes Sasser nabbed it.
Back to the subject at hand ... DITCH that 5.1.2, pull files from it if you need to, but WIPE IT OUT!