Charles,

Try Alter database set read_write. See http://bhaidar.net/cs/archive/2007/05/24/sql-server-express-and-read-only-databases.aspx
If it doesn't work then it's access rights issue.

>New Vista Ultimate box. Clean install of latest SQL 2008 RC. Then installed VS 2008 and SQL Express2005.
>
>From my XP box I detached two databases from an instance of SQL Express 2005. Copied the mdf and log files to the data folders of the two SQLs on the Vista box.
>
>SQL 2008 MS will attach the databases to the SQL Express 2005 server, but sees them as read only. I can then change them to readable. OK. Never saw that on XP boxes but ok.
>
>But the SQL 2008 will not allow the attach, saying the databases are read only or contain files that are read only.
>
>Both databases re-attach on the xp sql 2005 box with no problem.
>
>I assume I need to attach the database in 2008 with a T-sql CREATE DATABASE ... TO ATTACH TRUSTWORTHY ON but can't seem to get the syntax right.
>
>Guidance appreciated.
>
>TIA
>