Example

//adding Imaging name space
using System.Drawing.Imaging;
        privatevoid timer1_Tick(object sender, EventArgs e)
        {
            string filename;
            string dir;
            try
            {
                dir = "C:\\screen" + DateTime.Today.Day.ToString();
                filename = dir + "\\screen" + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + ".jpg";
                if (!Directory.Exists(dir))
                    Directory.CreateDirectory(dir);
 
 //Set the bitmap object to the size of the screen
                Bitmap screenShot = newBitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
 
 // Take the screenshot from the upper left corner to the right bottom corner
                Graphics screenGraphics = Graphics.FromImage(screenShot);
                screenGraphics.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
 
 // Save the screenshot
                screenShot.Save(filename, ImageFormat.Jpeg);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            
        }
 
        privatevoid Form1_Load(object sender, EventArgs e)
        {            
            timer1.Interval = 1000;
            timer1.Enabled = true;
        }

Screenshot