Get physical id for flash disk

You need to use Win32_LogicalDisk instead:

//Add a reference to System.Management.dll to the project.

using System;
using System.Management;

  public class LogicalDisk
  {

    public enum DiskType
    {
      Unknown,
      NoRootDirectory,
      Removable,
      Local,
      Network,
      CD,
      RAM
    } //DiskType

    public string Name;
    public long Freespace;
    public long Size;
    public DiskType DriveType;
    public string VolumeName;
    public string VolumeSerialNumber;

    public static LogicalDisk[] Disks
    {
      get
      {
        string query = "Select * from Win32_LogicalDisk";

        // Create a searcher for logical disks.
        ManagementObjectSearcher searcher = new ManagementObjectSearcher(query);

        // Get all the disk entries.
        ManagementObjectCollection results = searcher.Get();

        // Create an array of LogicalDisk entries.
        LogicalDisk[] listDisks = new LogicalDisk[results.Count];

        // Transfer the object settings to the array.
        int count = 0;

        foreach (ManagementObject diskObject in results)
        {
         
          LogicalDisk currentDisk = new LogicalDisk();
       
          currentDisk.Name = (string)diskObject["Name"];
          currentDisk.Freespace = Convert.ToInt64(diskObject["FreeSpace"]);
          currentDisk.Size = Convert.ToInt64(diskObject["Size"]);
          currentDisk.DriveType = (DiskType)Convert.ToInt32(diskObject["DriveType"]);
          currentDisk.VolumeName = (string)diskObject["VolumeName"];
          currentDisk.VolumeSerialNumber = (string)diskObject["VolumeSerialNumber"];
          listDisks[count] = currentDisk;

          count += 1;
        } //for

        return listDisks;

      } //get

    } //Disks

  }  //class

Look at VolumeSerialNumber.

Bob

Thanks Bob, but I do not want the volume serial number as this can change, I am after the factory set hardware serial.

I have learnt that not all of these drives have this number set, and this may be the case with my drive

That is a good point (I missed that from your question).  I don't know of any specific way to get the hardware serial from a flash drive.  I found some code on the Internet, but it didn't work either.

Bob

I pretty much have it sorted now, basically not all flash drives have a hardware serial number. But for the ones that do you can get the plug and play id using 'msinfo32' from the command line.

Or using VB.Net, you can get it using the following code
    Public Function GetHardwareSerialNumber_USB() As ArrayList
        Dim ar As New ArrayList
        Dim ms As ManagementObjectSearcher
        Dim moReturn As ManagementObjectCollection
        Dim mo As ManagementObject

        ms = New ManagementObjectSearcher("Select * from Win32_PnPEntity where name = 'USB Mass Storage Device'")
   
        moReturn = ms.Get()

        For Each mo In moReturn
            ar.Add(mo("DeviceID"))
        Next

        Return ar
    End Function

that will return all the PNP ids for all connected usb drives as an arraylist