After much searching I found the solution. When I install my application I need to give the system user "Network Service" permissions to the data directory where the databases are...

I tried to change the connection string for xp to have no user login, but it then fails if another user (even with admin permissions) tries to run the application...

If I am reading the bootstrap statement correctly, this should be mixed mode:

Arguments='/q /hideconsole /action=Install /features=SQL /instancename=SQLEXPRESS

/enableranu=1 /sqlsvcaccount="NT Authority\NetworkService"

/AddCurrentUserAsSqlAdmin /skiprules=RebootRequiredCheck

/IAcceptSQLServerLicenseTerms /SECURITYMODE="SQL" /SAPWD="xxxx"'

First off, I have started doing some testing and have found that if I don't use the user "sa" and password in the connection string on XP it allows my...