File permissions

I've been having problem in my asp.net 2 web when using the "User Instance=true" style connections to databases.

I would get ASP.NET event log errors like this:
Exception information:
Exception type: SqlException
Exception message: An attempt to attach an auto-named database for file c:\temp\dnn\dnn\dnn455\App_Data\Database.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

After I used ProcessMonitor it showed that the user ASPNET was trying to access C:\ directly after trying to open the database.mdf file I wanted open.

I had to give the ASPNET account read/execute permission to c:\, which was very scary.

Could someone please enlightenment me as to the correct file permissions needed to use databases in user instances?

Thanks,
Alex

You have the option to connect the User Instance to Management Studio because of known issues with User Instance. Try the link below for details.

http://blogs.msdn.com/sqlexpress/archive/2006/11/22/connecting-to-sql-express-user-instances-in-management-studio.aspx