how to fix system.outofmemoryexception in c# program

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Windows.Forms.VisualStyles;
using System.Configuration;
using System.IO;
//using System.IO.Packaging;
using System.Xml;
using System.Diagnostics;
using System.Text.RegularExpressions;

namespace FIlelib
{
    public partial class FilelibF : Form
    {
        public FilelibF()
        {
            InitializeComponent();
            scrollVal = 0;
        }
        string SqlStr;
        SqlCommand sqlcmd;
        //SqlDataReader sqldr;
        DataSet DS;
        string safefilename;
        SqlDataAdapter pagingAdapter;
        DataSet pagingDS;
        int scrollVal;

        public TextBox IdFileStudent = new TextBox();
        public TextBox Name = new TextBox();

        private void BtnNextpage_Click(object sender, EventArgs e)
        {
            scrollVal = scrollVal + 7;
            if (scrollVal > 1000000007)
            {
                scrollVal = 1000000000;
            }
            pagingDS.Clear();
            pagingAdapter.Fill(pagingDS, scrollVal, 7, "paging");
        }

        private void BtnPerviousPage_Click(object sender, EventArgs e)
        {
            scrollVal = scrollVal - 7;
            if (scrollVal <= 0)
            {
                scrollVal = 0;
            }
            pagingDS.Clear();
            pagingAdapter.Fill(pagingDS, scrollVal, 7, "paging");
        }

        private void BtnSave_Click(object sender, EventArgs e)
        {
            String sqlcon = "Data Source=SHADOW\\AL;Initial Catalog=Filelib;Integrated Security=True";
            SqlConnection cn = new SqlConnection(sqlcon);
            try
            {
                cn.Open();

                if (TxtFileName.Text == "" || TxtFilePath.Text == "")
                {
                    MessageBox.Show("Please Insert File or Name.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                else
                {
                    byte[] FileData = ReadFile(TxtFilePath.Text);
                    SqlStr = "insert into FilelibF (FilePath,FileData,FileName,FkIdFiles,SafeFileName) ";
                    SqlStr = SqlStr + "values(@FilePath, @FileData,@FileName,@FkIdFiles,@SafeFileName)";
                    SqlCommand SqlCom = new SqlCommand(SqlStr, cn);
                    SqlCom.Parameters.Add(new SqlParameter("@FilePath", (object)TxtFilePath.Text));
                    SqlCom.Parameters.Add(new SqlParameter("@FileData", (object)FileData));
                    SqlCom.Parameters.Add(new SqlParameter("@FileName", (object)TxtFileName.Text));
                    SqlCom.Parameters.Add(new SqlParameter("@FkIdFiles", (object)IdFileStudent.Text));
                    SqlCom.Parameters.Add(new SqlParameter("@SafeFileName", (object)safefilename));
                    SqlCom.ExecuteNonQuery();
                    SqlCom.CommandTimeout = 1000;
                    cn.Close();
                    clear();
                    fillGrid();
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        public void clear()
        {
            TxtFileName.Text = "";
            TxtFilePath.Text = "";
        }

        public void fillGrid()
        {
            String sqlcon = "Data Source=SHADOW\\AL;Initial Catalog=Filelib;Integrated Security=True";
            SqlConnection cn = new SqlConnection(sqlcon);

            try
            {

                cn.Open();
                SqlStr = "Select IdAttachBord,";
                SqlStr = SqlStr + " FkIdFiles,";
                SqlStr = SqlStr + " FilePath,";
                SqlStr = SqlStr + " FileData,";
                SqlStr = SqlStr + " FileName,";
                SqlStr = SqlStr + " SafeFileName";
                SqlStr = SqlStr + " from FilelibF";
                SqlStr = SqlStr + " where FkIdFiles ='" + IdFileStudent.Text + "'";
                SqlDataAdapter ADAP = new SqlDataAdapter(SqlStr, cn);
                pagingAdapter = new SqlDataAdapter(SqlStr, cn);
                pagingDS = new DataSet();
                DS = new DataSet();
                ADAP.Fill(DS, "FilelibF");
                pagingAdapter.Fill(pagingDS, scrollVal, 7, "paging");
                GridFile.DataSource = DS.Tables["FilelibF"];
                GridFile.DataSource = pagingDS;
                GridFile.DataMember = "paging";
                GridFile.Columns[4].HeaderText = "File Name";
                GridFile.Columns[0].Visible = false;
                GridFile.Columns[1].Visible = false;
                GridFile.Columns[2].Visible = false;
                GridFile.Columns[3].Visible = false;
                GridFile.Columns[5].Visible = false;



            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }



        }

        private byte[] ReadFile(string sPath)
        {
            //Initialize byte array with a null value initially.
            byte[] data = null;

            //Use FileInfo object to get file size.
            FileInfo fInfo = new FileInfo(sPath);
            //long numBytes = fInfo.Length;
            long OverTwoBillionAndSome = fInfo.Length;
            
            //Open FileStream to read file
            FileStream fStream = new FileStream(sPath, FileMode.Open, FileAccess.Read);



           


           
            //Use BinaryReader to read file stream into byte array.
            BinaryReader br = new BinaryReader(fStream);

            //When you use BinaryReader, you need to supply number of bytes to read from file.
            //In this case we want to read entire file. So supplying total number of bytes.
            data = br.ReadBytes((int)OverTwoBillionAndSome);


            //Close BinaryReader
            br.Close();

            //Close FileStream
            fStream.Close();

            return data;

        }

        private void BtnSelect_Click(object sender, EventArgs e)
        {
            //Ask user to select file.
            OpenFileDialog dlg = new OpenFileDialog();
            DialogResult dlgRes = dlg.ShowDialog();
            if (dlgRes != DialogResult.Cancel)
            {
                //Proviaclde file path in txtFilePath text box.
                TxtFilePath.Text = dlg.FileName;

                safefilename = dlg.SafeFileName;
            }
        }

        private void StudentFile_Load(object sender, EventArgs e)
        {
            fillGrid();
        }

        private void BtnDelete_Click(object sender, EventArgs e)
        {
            String sqlcon = "Data Source=SHADOW\\AL;Initial Catalog=Filelib;Integrated Security=True";
            SqlConnection cn = new SqlConnection(sqlcon);

            try
            {
                cn.Open();
                if (GridFile.SelectedRows[0].Index != -1)
                {
                    DialogResult dr = MessageBox.Show("Are you sure you want to delete this file?", "Confirmation",
                        MessageBoxButtons.YesNo);
                    if (dr == DialogResult.Yes)
                    {

                        SqlStr = "Delete from FilelibF where IdAttachBord = @SelectedCell";
                        sqlcmd = new SqlCommand(SqlStr, cn);
                        sqlcmd.Parameters.Add(new SqlParameter("SelectedCell", GridFile.SelectedRows[0].Cells[0].Value));
                        sqlcmd.ExecuteNonQuery();


                        //...........................
                        GridFile.Rows.RemoveAt(GridFile.SelectedRows[0].Index);

                    }
                    else if (dr == DialogResult.No)
                    {

                    }
                }
                else
                {
                    MessageBox.Show("Please Select a Row.", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
            }
            finally
            {
                cn.Close();
            }
        }

        private void BtnDisplay_Click(object sender, EventArgs e)
        {

            if (GridFile.CurrentCell == null)
            {
                MessageBox.Show("Please Select A Row.");
                return;
            }
            DataTable dt = new DataTable();
            int SelectedRow = GridFile.CurrentCell.RowIndex;
            string OriginalPath = GridFile.SelectedRows[0].Cells[2].Value.ToString();
            string tempsafefilename = GridFile.SelectedRows[0].Cells[5].Value.ToString();
            saveFileDialog2.FileName = OriginalPath;
            string FileName = saveFileDialog2.FileName;
            //.......
            if (File.Exists(FileName))
            {
                Process.Start(FileName);
            }
            else
            {

                byte[] FileData = (byte[])DS.Tables["FilelibF"].Rows[SelectedRow]["FileData"];

                String newfile = @"C:\Temp";
                DirectoryInfo l_dDirInfo = new DirectoryInfo(newfile);
                if (l_dDirInfo.Exists == false)
                {
                    Directory.CreateDirectory(newfile);
                }

                string NewPath = newfile + "\\" + tempsafefilename;
                using (FileStream fs = new FileStream(NewPath, FileMode.Create))
                {
                    fs.Write(FileData, 0, FileData.Length);

                    Process.Start(NewPath);

                }

            }
        }

        private void GridFile_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (GridFile.CurrentCell == null)
            {
                MessageBox.Show("Please Select a Row.");
                return;
            }
            DataTable dt = new DataTable();
            int SelectedRow = GridFile.CurrentCell.RowIndex;
            string OriginalPath = GridFile.SelectedRows[0].Cells[2].Value.ToString();
            string tempsafefilename = GridFile.SelectedRows[0].Cells[5].Value.ToString();
            saveFileDialog2.FileName = OriginalPath;
            string FileName = saveFileDialog2.FileName;
            //.......
            if (File.Exists(FileName))
            {
                Process.Start(FileName);
            }
            else
            {

                byte[] FileData = (byte[])DS.Tables["FilelibF"].Rows[SelectedRow]["FileData"];

                String newfile = @"C:\Temp";
                DirectoryInfo l_dDirInfo = new DirectoryInfo(newfile);
                if (l_dDirInfo.Exists == false)
                {
                    Directory.CreateDirectory(newfile);
                }

                string NewPath = newfile + "\\" + tempsafefilename;
                using (FileStream fs = new FileStream(NewPath, FileMode.Create))
                {
                    fs.Write(FileData, 0, FileData.Length);

                    Process.Start(NewPath);


                }