Create (Insert) new user using ASP.Net CreateUserWizard in C#

Check below sample.

HTML

<asp:CreateUserWizard ID="CreateUserWizard1" runat="server" OnCreatedUser="CreateUserWizard1_CreatedUser">
    <WizardSteps>
        <asp:CreateUserWizardStep ID="CreateUserWizardStep1" runat="server">
            <ContentTemplate>
                <table border="0">
                    <tr>
                        <td align="center" colspan="2">Sign Up for Your New Account</td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName">User Name:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="UserName" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="UserNameRequired" runat="server" ControlToValidate="UserName"
                                ErrorMessage="User Name is required." ToolTip="User Name is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password">Password:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="Password" runat="server" TextMode="Password"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="PasswordRequired" runat="server" ControlToValidate="Password"
                                ErrorMessage="Password is required." ToolTip="Password is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="ConfirmPasswordLabel" runat="server" AssociatedControlID="ConfirmPassword">Confirm Password:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="ConfirmPassword" runat="server" TextMode="Password"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="ConfirmPasswordRequired" runat="server" ControlToValidate="ConfirmPassword"
                                ErrorMessage="Confirm Password is required." ToolTip="Confirm Password is required."
                                ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="EmailLabel" runat="server" AssociatedControlID="Email">E-mail:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="Email" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="EmailRequired" runat="server" ControlToValidate="Email"
                                ErrorMessage="E-mail is required." ToolTip="E-mail is required." ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="QuestionLabel" runat="server" AssociatedControlID="Question">Security Question:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="Question" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="QuestionRequired" runat="server" ControlToValidate="Question"
                                ErrorMessage="Security question is required." ToolTip="Security question is required."
                                ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="right">
                            <asp:Label ID="AnswerLabel" runat="server" AssociatedControlID="Answer">Security Answer:</asp:Label></td>
                        <td>
                            <asp:TextBox ID="Answer" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="AnswerRequired" runat="server" ControlToValidate="Answer"
                                ErrorMessage="Security answer is required." ToolTip="Security answer is required."
                                ValidationGroup="CreateUserWizard1">*</asp:RequiredFieldValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="center" colspan="2">
                            <asp:CompareValidator ID="PasswordCompare" runat="server" ControlToCompare="Password"
                                ControlToValidate="ConfirmPassword" Display="Dynamic" ErrorMessage="The Password and Confirmation Password must match."
                                ValidationGroup="CreateUserWizard1"></asp:CompareValidator>
                        </td>
                    </tr>
                    <tr>
                        <td align="center" colspan="2" style="color: red">
                            <asp:Literal ID="ErrorMessage" runat="server" EnableViewState="False"></asp:Literal>
                        </td>
                    </tr>
                </table>
            </ContentTemplate>
        </asp:CreateUserWizardStep>
        <asp:CompleteWizardStep ID="CompleteWizardStep1" runat="server">
        </asp:CompleteWizardStep>
    </WizardSteps>
</asp:CreateUserWizard>

Namespaces

using System.Configuration;
using System.Data.SqlClient;
using System.Web.Security;

Code

protected void CreateUserWizard1_CreatedUser(object sender, EventArgs e)
{
    MembershipUser membershipUser = Membership.GetUser(CreateUserWizard1.UserName);
    Guid userId = (Guid)membershipUser.ProviderUserKey;
    string firstName = ((TextBox)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("FirstName")).Text;
    string lastName = ((TextBox)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("LastName")).Text;
    string connectionString = ConfigurationManager.ConnectionStrings["MembershipConnectionString"].ConnectionString;
    string insertSql = "INSERT INTO User_Profile(UserId, FirstName, LastName) VALUES (@UserId, @FirstName, @LastName)";
    using (SqlConnection con = new SqlConnection(connectionString))
    {
        using (SqlCommand cmd = new SqlCommand(insertSql, con))
        {
            cmd.Parameters.AddWithValue("@UserId", userId);
            cmd.Parameters.AddWithValue("@FirstName", firstName);
            cmd.Parameters.AddWithValue("@LastName", lastName);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
}