C#

<pre lang="c#">
        public static void Download(String strURLFileandPath, String strFileSaveFileandPath)
        {
            HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(strURLFileandPath);
            HttpWebResponse ws = (HttpWebResponse)wr.GetResponse();
            Stream str = ws.GetResponseStream();
            byte[] inBuf = new byte[100000];
            int bytesToRead = (int)inBuf.Length;
            int bytesRead = 0;
            while (bytesToRead > 0)
            {
                int n = str.Read(inBuf, bytesRead, bytesToRead);
                if (n == 0)
                    break;
                bytesRead += n;
                bytesToRead -= n;
            }
            try
            {
                
                FileStream fstr = new FileStream(strFileSaveFileandPath, FileMode.OpenOrCreate, FileAccess.Write);
                fstr.Write(inBuf, 0, bytesRead);
                str.Close();
                fstr.Close();
            }
            catch (Exception e) {
                MessageBox.Show(e.Message);
            }
            
        }



        private void button2_Click(object sender, EventArgs e)
        {
            if (phpurl.Text == "") {
                MessageBox.Show("Invalid Url");
            }
            else if (Uri.IsWellFormedUriString(phpurl.Text, UriKind.Absolute) == false)
            {
                MessageBox.Show("Invalid Url");
            }
            else {
                Download(phpurl.Text, @"D:\test");
            }

            
        } 

<?xml version="1.0" encoding="utf-8"?>
<asmv1:assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/>
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
    <security>
      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
        <!-- UAC Manifest Options
            If you want to change the Windows User Account Control level replace the 
            requestedExecutionLevel node with one of the following.

        <requestedExecutionLevel  level="asInvoker" uiAccess="false" />
        <requestedExecutionLevel  level="requireAdministrator" uiAccess="false" />
        <requestedExecutionLevel  level="highestAvailable" uiAccess="false" />

            Specifying requestedExecutionLevel node will disable file and registry virtualization.
            If you want to utilize File and Registry Virtualization for backward 
            compatibility then delete the requestedExecutionLevel node.
        -->
        <requestedExecutionLevel  level="requireAdministrator" uiAccess="false" />
      </requestedPrivileges>
    </security>
  </trustInfo>
  
  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
    <application>
      <!-- A list of all Windows versions that this application is designed to work with. Windows will automatically select the most compatible environment.-->

      <!-- If your application is designed to work with Windows 7, uncomment the following supportedOS node-->
      <!--<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>-->
      
    </application>
  </compatibility>
  
  <!-- Enable themes for Windows common controls and dialogs (Windows XP and later) -->
  <!-- <dependency>
    <dependentAssembly>
      <assemblyIdentity
          type="win32"
          name="Microsoft.Windows.Common-Controls"
          version="6.0.0.0"
          processorArchitecture="*"
          publicKeyToken="6595b64144ccf1df"
          language="*"
        />
    </dependentAssembly>
  </dependency>-->

</asmv1:assembly>

FileVersionInfo fsi = FileVersionInfo.GetVersionInfo(@"C:\Windows\system32\drivers\ftdibus.sys");
String AppPath = Directory.GetCurrentDirectory();

ServiceController[] scDevices = ServiceController.GetDevices();

private void dataGridView1_RowValidating(object sender, DataGridViewCellCancelEventArgs e)
    {

        if (dataGridView1.Rows[e.RowIndex].IsNewRow)
        {
            return;
        }

            string customer = dataGridView1.Rows[e.RowIndex].Cells["customerID"].FormattedValue.ToString();

            decimal paid;
            decimal.TryParse(dataGridView1.Rows[e.RowIndex].Cells["amountPaid"].FormattedValue.ToString(), out paid);

            bool isCredit;
            bool.TryParse(dataGridView1.Rows[e.RowIndex].Cells["isCreditSale"].FormattedValue.ToString(), out isCredit);

            if (isCredit == true && string.IsNullOrEmpty(customer))
            {
                MessageBox.Show("Please enter a customer name for this credit sale", "", MessageBoxButtons.OK, MessageBoxIcon.Error);
                e.Cancel = true;
            }   
    }