This article assumes you are running the following configuration in MSDE:
- mixed mode authentication
- network protocols enabled


Download the MSDE SP4 installer:

http://www.microsoft.com/downloads/info.aspx?na=46&p=6&SrcDisplayLang=en&SrcCategoryId=&SrcF…

1. Open a command prompt.

2. From the command prompt, use the cd command to navigate to the folder that contains the MSDE 2000 SP4 setup utility:

cd c:\MSDESP4Folder\MSDE

where
c:\MSDESP4Folder is either the path to the folder into which you
extracted the MSDE 2000 SP4 files, or the MSDE 2000 SP4 folder on the
SQL Server 2000 SP4 CD.

3. Execute the following commands:

setup /upgradesp sqlrun DISABLENETWORKPROTOCOLS=0 SECURITYMODE=SQL UPGRADEUSER=sa UPGRADEPWD=sa_password /L*v C:MSDELog.log

where sa_password is the current sa password for your MSDE installation.