A few weeks ago I succeeded in installing DotNetNuke and was able to begin the creation of sites. Then I had a pause from the development of DotNetNuke.

In the meantime I deleted the user-account "ASP_NET". I've got an idea that this is the cause of the error.

Because now when I try to enter the "http://localhost/DotNetNuke/Default.aspx" I get the "An error has occurred.
An error has occurred."

So I tried the "http://localhost/DotNetNuke/Install/install.aspx" which ends up after the "Configure Database Connection" in "Failed to generate a user instance of SQL Server due to failure in retrieving the user's local application data path."

I tried to check for permission in the SQL Server Express and in the web.config. It looks like the database is accessible and the web.config looks alright (well, it actually looks a little confusing but the places it seemed like important the settings were alright).

But then howcome I can't get past the error? Is the best solution that I complettely delete DotNetNuke (and Sql Server) on my system and then follow the guide on: "http://www.adefwebserver.com/DotNetNukeHELP/DNN4_DevelopmentEnvironment/DNNDevelopmentWindowsVista.htm" ?

I'm using Vista Ultimate and IIS7.

Thanks in advance!