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

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.....

  1. Use Vista's Maximum Security (I never would.)
  2. Lighten Up a Bit (You know, turn of UAC and such.)
  3. Make security on this vista box just like Windows XP
  4. Make me a GOD on this box (Super Grand Admin - I accept the responsibility.)
  5. 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."


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.

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.