Contributed By: Cliff Hobbs [MVP SMS]
Microsoft have released SQL 2000 SP3a which you can download from:

http://www.microsoft.com/downloads/details.aspx?familyid=90dcd52c-0488-4e46-afbf-acace5369fa3&displaylang=en

If you’ve already applied SP3 then you don’t need SP3a which is really for those who haven’t applied SP3 yet (you should apply SP3a now instead of SP3 if you haven’t already applied SP3), and for those MSDE users who want to use the new "disable network protocols" option.

For more information see:
http://www.microsoft.com/sql/downloads/2000/sp3.asp.

For a list of what’s fixed in SP3a see the Knowledge Base Article 306908 'INF: List of Bugs Fixed by SQL Server 2000 Service Packs'.