code to download images or files

you can simply call WebClient.DownloadFile:
 
string myFilename = @"c:\MyImg.jpg";
using(WebClient client = new WebClient())
{
  client.DownloadFile("http://www.abc.com/car.jpg", myFilename);
}


** But before that you need to validate the availability of the image

string localFilename = @"c:\localpath\tofile.jpg";
using(WebClient client = new WebClient())
{
  client.DownloadFile("http://www.example.com/image.jpg", localFilename);
}