WIN32_Processor::Is ProcessorId Unique for all computers

c# winapi wmi
Mohsan picture Mohsan · Jul 9, 2009 · Viewed 36.8k times · Source

I want to use some thing unique for a licensing system. i decided to use ProcessorID from Win32_Processor Management class.

I tried on two different systems with same processor type..

It shows me same processorID for both system. i am using this code

public static String GetCPUId()
{
    String processorID = "";

    ManagementObjectSearcher searcher = new ManagementObjectSearcher(
        "Select * FROM WIN32_Processor");

    ManagementObjectCollection mObject = searcher.Get();

    foreach (ManagementObject obj in mObject)
    {
        processorID = obj["ProcessorId"].ToString();
    }

    return processorID;
}

Answer

casperOne picture casperOne · Jul 9, 2009

No, it can't be guaranteed that it will be unique, as the processor might not even support the CPUID instruction, in which case, the call can't be guaranteed to succeed.

Also, you are neglecting that a machine might have multiple processors in it, so getting the id of a single processor doesn't help.

As others have indicated, if you want to get a unique id for the system, your best bet is to create an id which is an amalgam of various component ids on the system.

A hash (and not just any, but one that has very few collisions) of various values of the hardware could suffice. You'd probably want to use things that are fairly embedded in the system, such as the processor, motherboard info, but not things easily detached/changed, such as USB drives/hubs/etc.

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