There seems to be major issues when installing this service pack. After I installed it, I never got past the “blue screen of death”. I thought it was just something strange on my machine, until I went to a user group meeting that night. I found out that other people were having other install issues. I and others lost all data on our machines and had to reformat and reinstall everything! Make sure you make a backup before installing this service pack!
Be careful Installing Windows 2000 SP3