SQL Server 2000 is at the end of its product lifecycle and will lose its "extended support" from Microsoft on Tuesday, April 9.
The loss of extended support means no more security updates will be delivered to customers via Microsoft's update service. Remedies for organizations still using SQL Server 2000 are to upgrade the product (Microsoft is recommending moving to its current SQL Server 2012 product) or pay for "custom support" through Microsoft Premier Support services, according to a Microsoft announcement.
It's possible to continue to run SQL Server 2000 after April 9, but that approach isn't recommended by Microsoft for security reasons. Self-help resources, such as Knowledge Base articles and troubleshooting tools, will continue to be available online for a minimum of 12 months.