Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies.

Okay for sanities sake I have redone my code and stripped out everything bar the Editor.

Errors:

1) Could not load file or assembly 'AjaxControlToolkit' or one of its dependencies. However I think I have...? 

2) Unknown server tag 'HTMLEditor:Editor' 

Default.aspx

<%@ Page Title="Home Page" Language="VB" MasterPageFile="~/Site.Master" AutoEventWireup="false"
    CodeFile="Default.aspx.vb" Inherits="_Default" %><asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent"></asp:Content><asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent"><%@ Register
    Assembly="AjaxControlToolkit"
    Namespace="AjaxControlToolkit.HTMLEditor"
    TagPrefix="HTMLEditor" %><HTMLEditor:Editor runat="server"
        Height="300px"
        Width="100%"
        AutoFocus="true"
/>

Default.aspx.vb

Partial Class _Default
    Inherits System.Web.UI.Page

End Class

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><connectionStrings><add name="ApplicationServices"
         connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true"
         providerName="System.Data.SqlClient" /></connectionStrings><system.web><compilation debug="false" strict="false" explicit="true" targetFramework="4.0" /><authentication mode="Forms"><forms loginUrl="~/Account/Login.aspx" timeout="2880" /></authentication><membership><providers><clear/><add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices"
             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="ApplicationServices" applicationName="/"/></providers></profile><roleManager enabled="false"><providers><clear/><add name="AspNetSqlRoleProvider" type="System.Web.Security.SqlRoleProvider" connectionStringName="ApplicationServices" applicationName="/" /><add name="AspNetWindowsTokenRoleProvider" type="System.Web.Security.WindowsTokenRoleProvider" applicationName="/" /></providers></roleManager></system.web><system.webServer><modules runAllManagedModulesForAllRequests="true"/></system.webServer></configuration>