Sharing Security Developments, and Best Practices for corporate and home users
The release of Service Pack 4 for SQL-Server 2000 was on May 6, 2005. After lab testing, this new Service Pack will be worthwhile to install for improved security and to provide bug fixes for functional issues.. 
SQL-Server 2000 SP4 HOME PAGE
SQL-Server 2000 SP4 - List of Security and Bug Fixes
DOWNLOAD LINK SQL-SERVER 2000 SP4