How to prevent Blaster Worm attack?

Always, enable the Internet Connection Firewall in Windows XP.

Download and apply the patch MS03-039 here:

[A Buffer Overrun in RPCSS Could Allow an Attacker to Run Malicious Programs]

More Information - "Blaster" Worm

A tool is available to remove Blaster worm and Nachi worm infections from computers that are running Windows 2000 or Windows XP:

Learn more about Firewalls - Windows XP ICF:

Virus Alert About the Blaster Worm and Its Variants:

What You Should Know About the Blaster Worm

TCP and UDP Port Assignments in Windows 2000: