ghhfgh/Form2.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            var db = new DataClasses1DataContext();
            var data = new Users
                {
                Login=textBox1.Text,
                Password=textBox2.Text
            };
            db.Users.InsertOnSubmit(data);
            db.SubmitChanges();
            MessageBox.Show("Пользователь успешно добавлен!");
            Form1 p = new Form1();
            p.Show();
        }
    }
}