HOWTO: Distribute the Microsoft Data Engine (MSDE) With the Package and Deployment Wizard (PDW) (Q231923)
http://support.microsoft.com/search/preview.aspx?scid=kb;en-us;Q231923
SAMPLE: Setup1.exe Fully Automating MSDE Setup with the Package and Deployment Wizard (PDW) (Q234626)
http://support.microsoft.com/search/preview.aspx?scid=kb;en-us;Q234626