I suggest posting your <connectionstring> and your <appsetting> so that other people can look at it.  I changed my web.config from (localhost)/sql...  to Arsenic/SQLExpress..  (Arsenic being my computer's name and the last being the default name sql was installed under.

Hi wegnwa

I had the same errors installing the Starter Kit in Windows XP Pro and MS SQL Server 2005 Express Ed. So try this steps:

1. Doubleklick the file DotNetNuke_4.0.3_StarterKit.vsi
   (to do this, you have to install MS Visual Studio 2005 or MS Visual Web Developer 2005 Express Edition)
2. Click next, click yes, click finish, click close
   -> this installs DotNetNuke templates for Visual Studio.
3. Start MS Visual Studio 2005 or MS Visual Web Developer 2005 Express Edition
4. In the File-Menu choose 'New/Web Site...'.
   In Web Developer click 'File/New Web Site...'.
5. As location choose 'HTTP', type in your site location, as example 'http://localhost/DotNetNuke', set 'Visual Basic' as language and under My Tamplates choose 'DotNetNuke Web Applikation Framework'. Click OK.
6. Now rename 'release.config' in the Solution Explorer to 'web.config'. I used the default settings, no changes.
   
   The Next steps ar more or less described in http://localhost/DotNetNuke/Documents/Welcome.html:
   
7. Now rightclick at App_Data in the Solution Explorer in Visual Studio. Choose 'Add New Item...' Click at SQL Database, click Add.
   (If you change the database name, you have to change the web.config file.)
8. Configure the IIS virtual directory according to 'http://localhost/DotNetNuke/Documents/WebServerConfig.html' but in the tab 'Documents' add 'default.aspx'
9. Set the <pc name>\ASPNET account according to 'http://localhost/DotNetNuke/Documents/NTFSConfig.html' but to be certain reapply the rights to subfolders and files with the checkmark 'Replace permission entries on all child objects ...' on the Advanced Securitty Settings Dialog of your virtual directory folder.
   
   
10. Now put the <pc name>\ASPNET account into the local security group 'SQLServer2005MSSQLUser$<pc name>$SQLEXPRESS. This gives your Web application the right to autoattach the database.mdf and also the access to the data in the database. But be aware, the ASPNET account has now the sysadmin role on the SQL Server. (I think, no big problem on a developer pc.)
11. Now type Ctrl-F5

Good luck
AnAmigian