Asp.net Website administration tool error - asp.net

Question

I am trying to login for one, and it doesnt let me. Im quite sure it has to do with the web.config file. It stopped working roughly around the same time i used the administration tool to assign roles to (users and staff). Now after i click security on the website administration tool homepage it gives me an error that i cannot connect ot my sql database. I dont understand. I just want to be able to allow users to log in and be redirected to a page i want and staff the same (also having full access to the site while users only to one page that i insist upon). Heres me web.config:
<?xml version="1.0"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>
</configSections>
<appSettings>
<add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\TempImageFiles\;" />
</appSettings>
<system.webServer>
<validation validateIntegratedModeConfiguration="false" />
<handlers>
<remove name="ChartImageHandler" />
<add name="ChartImageHandler" preCondition="integratedMode" verb="GET,HEAD,POST"
path="ChartImg.axd" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</handlers>
</system.webServer>
<connectionStrings>
<add name="DefaultConnection" connectionString="Data Source=(LocalDb)\v11.0;Initial Catalog=aspnet-WebApplication4-20140921152333;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnet-WebApplication4-20140921152333.mdf" providerName="System.Data.SqlClient"/>
<add name="PizzaConnectionString" connectionString="Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\PizzaOrders.mdf;Integrated Security=True;Connect Timeout=30" providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<httpHandlers>
<add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
validate="false" />
</httpHandlers>
<compilation debug="true" strict="false" explicit="true" targetFramework="4.5">
<assemblies>
<add assembly="System.Data.Services.Client, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
</assemblies>
</compilation>
<httpRuntime targetFramework="4.5"/>
<pages>
<namespaces>
<add namespace="System.Web.Optimization" />
</namespaces>
<controls>
<add tagPrefix="webopt" namespace="Microsoft.AspNet.Web.Optimization.WebForms"
assembly="Microsoft.AspNet.Web.Optimization.WebForms" />
<add tagPrefix="ajaxToolkit" namespace="AjaxControlToolkit" assembly="AjaxControlToolkit" />
<add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting"
assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</controls>
</pages>
<authentication mode="Forms">
<forms loginUrl="~/Account/Login.aspx" timeout="2880"/>
</authentication>
<profile defaultProvider="DefaultProfileProvider">
<providers>
<add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/"/>
</providers>
</profile>
<membership>
<providers>
<add connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</providers>
</membership>
<roleManager enabled="true">
<providers>
<add connectionStringName="DefaultConnection" applicationName="/" name="DefaultRoleProvider" type="System.Web.Providers.DefaultRoleProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</providers>
</roleManager>
<!--
If you are deploying to a cloud environment that has multiple web server instances,
you should change session state mode from "InProc" to "Custom". In addition,
change the connection string named "DefaultConnection" to connect to an instance
of SQL Server (including SQL Azure and SQL Compact) instead of to SQL Server Express.
-->
<sessionState mode="InProc" customProvider="DefaultSessionProvider">
<providers>
<add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection"/>
</providers>
</sessionState>
</system.web>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>
</entityFramework>
</configuration>

Answer 1

Change the connection string "DefaultConnection" to connect to an instance of SQL Server.