private DataGridViewRowUpgrade FindRow(Host host)
 {
     foreach (DataGridViewRowUpgrade row in dataGridView1.Rows)
     {
         if (host == null && row.Host == null)
             return row;
         if (host != null && row.Host != null && host.Equals(row.Host))
             return row;
     }
     throw new Exception("Row not found");
 }