SQL Express - "Failed generate a user instance..."

Error Details

2010-04-11 19:20:01.73 spid7s      Script level upgrade for database 'master' failed because upgrade step 'repl_master.sql' encountered error 5598, state 1, severity 16. This is a serious error condition which might interfere with regular operation and the database will be taken offline. If the error happened during upgrade of the 'master' database, it will prevent the entire SQL Server instance from starting. Examine the previous errorlog entries for errors, take the appropriate corrective actions and re-start the database so that the script upgrade steps run to completion.
2010-04-11 19:20:01.73 spid7s      Error: 3417, Severity: 21, State: 3.
2010-04-11 19:20:01.73 spid7s      Cannot recover the master database. SQL Server is unable to run. Restore master from a full backup, repair it, or rebuild it. For more information about how to rebuild the master database, see SQL Server Books Online.
2010-04-11 19:20:01.73 spid7s      SQL Trace was stopped due to server shutdown. Trace ID = '1'. This is an informational message only; no user action is required.

Ref: http://blogs.msdn.com/joestagner/archive/2008/03/12/sql-express-failed-generate-a-user-instance.aspx?CommentPosted=true#commentmessage

I Love SQL Server Express. I write demos. Lots of them. SQL Express is great because it's free and works with .MDF files so that I can just bundle up the database with my demo and folks can download a demo, run, and experiment.

I'm "learning" to love Windows Vista.

My only real complaint is that we OVER DID security. I want a switch that says.....

Use Vista's Maximum Security (I never would.)
Lighten Up a Bit (You know, turn of UAC and such.)
Make security on this vista box just like Windows XP
Make me a GOD on this box (Super Grand Admin - I accept the responsibility.)
Windows 98 Mode (TURN IT ALL OFF.)

Life's been very busy these days and I'm working on some new illustrative demos for my AJAX World Talks next week.

Trying to connect to my SQL Express database from my ASP.NET code yields the following message.

"Failed to generate a user instance of SQL Server due to a failure in starting the process for the user instance. The connection will be closed."

... "a failure."

CAN YOU BE A BIT MORE SPECIFIC ????????

I know, I know, this is a typical Microsoft error message.

I know SQL Express installers locked down to some extend so I thought maybe the issue was disabled protocols as I was carrying forward some code, but alas - nothing seamed to help. I tried all the configuration tools, used the surface area tool and added everyone to the SQL admin's groups. NOTHING

After searching and playing for some time I got things working again and wanted to share the solution.

If you're running from the IDE then you are running as yourself so:

Delete C:\Documents and Settings\USERNAME\Local Settings\Application Data\Microsoft\Microsoft SQL Server Data\SQLEXPRESS.

I am using Windows 7, the path is

"C:\Users\xxxxxx\AppData\Local\Microsoft\Microsoft SQL Server Data"

If you're running via IIS the user is usually ASPNET so....

Delete C:\Documents and Settings\COMPUTERNAME\USERNAME\Local Settings\Application Data\Microsoft\Microsoft SQL Server Data\SQLEXPRESS

Hope you found this and it saves you some time.