Is anyone out there using microsoft sql express 2005 with an appian installation

Do you have another -ds file in the directory. Could you have accidently made a copy of this file (probably named Copy of Appian-ds.xml???)
If not, try shutting down JBOSS, clear Cache and restart.
In order to clear Cache, you need to delete contents of $APPIAN\\bin\\jboss\\jboss-as-7.1.1.Final\\standalone\          mp directory.

And why is your server name //localhost?

Can you create a JDBC URL with the above details and see if that works? That's why I was alluding to testing using one of the SQL client tools so you know you have the correct connection string to use here.

Do you have another -ds file in the directory. Could you have accidently made a copy of this file (probably named Copy of Appian-ds.xml???)
If not, try shutting down JBOSS, clear Cache and restart.
In order to clear Cache, you need to delete contents of $APPIAN\\bin\\jboss\\jboss-as-7.1.1.Final\\standalone\          mp directory.

And why is your server name //localhost?

Can you create a JDBC URL with the above details and see if that works? That's why I was alluding to testing using one of the SQL client tools so you know you have the correct connection string to use here.