I have a named MSDE Instance which is created by 'sa' user.
I want to upgrade this instance to SQL Server Express 2005.
I need to do it using the command line options, i am using the following command line option :

start /wait setup.exe /qn INSTANCENAME=<Instance Name> UPGRADE=SQL_Engine UPGRADEUSER=sa SAPWD=<SAPWD> SECURITYMODE=SQL DisableNetworkProtocols = 0

I am getting error log in failed for 'sa' User but i can connect the above instance in SQL Management Studio providing the same password.

Can any one give me pointer for cause of error?