web.config error - asp.net

Question

Hello everyone can someone help me with my web.config file? I am having error. I just want you guys to look at it and if there are errors someone that needs correction. Thank you all:
This is the error message:
Warning 1 The 'targetFramework' attribute is not declared. G:\display images in gridview\Web.config 17 62 Miscellaneous Files
Message 2 Could not find schema information for the element 'modules'. G:\display images in gridview\Web.config 51 7 Miscellaneous Files
Message 3 Could not find schema information for the attribute 'runAllManagedModulesForAllRequests'. G:\display images in gridview\Web.config 51 15 Miscellaneous Files
Error 4 The 'configuration' start tag on line 10 does not match the end tag of 'system.web'. Line 101, position 4. (C:\Users\Collins\Documents\Visual Studio 2005\WebSites\living to please god world\web.config line 101)
Here is the Web.config file:
<?xml version="1.0"?>
<configuration>
<connectionStrings>
<add name="ConnectionString"
connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\ASPNETDB.MDF;Integrated Security=True;User Instance=True"
providerName="System.Data.SqlClient"/>
</connectionStrings>
<system.web>
<customErrors mode="Off"/>
<compilation debug="true"/>
</system.web>
<pages>
<namespaces>
<clear/>
<add namespace="System"/>
<add namespace="System.Collections"/>
<add namespace="System.Collections.Specialized"/>
<add namespace="System.Configuration"/>
<add namespace="System.Text"/>
<add namespace="System.Text.RegularExpressions"/>
<add namespace="System.Web"/>
<add namespace="System.Web.Caching"/>
<add namespace="System.Web.SessionState"/>
<add namespace="System.Web.Security"/>
<add namespace="System.Web.Profile"/>
<add namespace="System.Web.UI"/>
<add namespace="System.Web.UI.WebControls"/>
<add namespace="System.Web.UI.WebControls.WebParts"/>
<add namespace="System.Web.UI.HtmlControls"/>
</namespaces>
</pages>
<membership>
<providers>
<clear/>
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="LocalSqlServer" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/"/>
</providers>
</membership>
<profile>
<providers>
<clear/>
<add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="LocalSqlServer" applicationName="/"/>
</providers>
</profile>
<authentication mode="Forms">
<forms loginUrl="login.aspx" defaultUrl="Default.aspx"/>
</authentication>
<authorization>
<allow users="*"/>
</authorization>
<location path="PhotoAdmin">
<system.web>
<authorization>
<deny users="?"/>
</authorization>
</system.web>
</location>
<system.net>
<mailSettings>
<smtp from="some#example.com">
<network host="relay-hosting.example.net" password="" userName=""/>
</smtp>
</mailSettings>
</system.net>
</configuration>

Answer 1

Well there are several things that are messed up.
The targetFramework attribute must be specified if the application pool that you are using is set up to use .Net Framework 4. If this is the case then you should have the following section under system.web:
<compilation debug="true" targetFramework="4.0" />
The system.web section is closed too earlier. The sections 'pages', 'membership', 'profile', 'authentication' and 'authorization' must be subsections of system.web.