Safest way to get processor ID or some hardware info

Question

I need to get any info to identify a machine and what I was using so far was the following:

    internal static string GetProcessorId()
    {
        try
        {
            StringBuilder sb = new StringBuilder();
            using (System.Management.ManagementClass theClass = new System.Management.ManagementClass("Win32_Processor"))
            {
                using (System.Management.ManagementObjectCollection theCollectionOfResults = theClass.GetInstances())
                {
                    foreach (System.Management.ManagementObject currentResult in theCollectionOfResults)
                    {
                        sb.Append(currentResult["ProcessorID"].ToString());
                    }
                }
            }
            return sb.ToString();
        }
        catch (Exception exception)
        {
            Console.WriteLine(exception.Message);
            return "";
        }
    }

But when I run this on Windows XP (from a Virtual Machine), my currentResult["ProcessorID"] is null. I'm not sure if it is because I'm using a virtual machine, but it might be because is XP. Anyway, I'm not very trustful of this code. Is it safe enough? Should I get a computer Id some other way? This is all part of a licensing system I'm developing.

Answer 1

For a small tool I wrote (Windows Forms .NET 2.0), I needed something similar.

I wrote a helper class that simply uses some common information like HDD serial number through PInvoke of the GetVolumeInformation function.

This is by no way really safe or bullet-proof, but accurate enough to fit my needs.

(If you are interested this is the tool, if I'm allowed to link to)