Generating a unique machine id

Question

I need to write a function that generates an id that is unique for a given machine running a Windows OS   Currently  I m using WMI to query various hardware parameters and concatenate them together and hash them to derive the unique id  My question is  what are the suggested parameters I should use   Currently  I m using a combination of bios cpu disk data to generate the unique id  And am using the first result if multiple results are there for each metric   However  I ran into an issue where a machine that dual boots into 2 different Windows OS generates different site codes on each OS  which should ideally not happen   For reference  these are the metrics I m currently using   Win32 Processor UniqueID ProcessorID Name Manufacturer MaxClockSpeed Win32 BIOS Manufacturer Win32 BIOS SMBIOSBIOSVersion IdentificationCode SerialNumber ReleaseDate Version Win32 DiskDrive Model  Manufacturer  Signature  TotalHeads Win32 BaseBoard Model  Manufacturer  Name  SerialNumber Win32 VideoController DriverVersion  Name

User · Answer

For one of my applications  I either use the computer name if it is non-domain computer  or the domain machine account SID for domain computers  Mark Russinovich talks about it in this blog post  Machine SID      The final case where SID duplication would be an issue is if a distributed application used machine SIDs to uniquely identify computers  No Microsoft software does so and using the machine SID in that way doesn   t work just for the fact that all DC   s have the same machine SID  Software that relies on unique computer identities either uses computer names or computer Domain SIDs  the SID of the computer accounts in the Domain      You can access the domain machine account SID via LDAP or System DirectoryServices

User · Answer

You should look into using the MAC address on the network card  if it exists   Those are usually unique but can be fabricated  I ve used software that generates its license file based on your network adapter MAC address  so it s considered a fairly reliable way to distinguish between computers

User · Answer

Why not use the MAC address of your network card

User · Answer

Maybe cheating a little  but the MAC Address of a machines Ethernet adapter rarely changes without the motherboard changing these days

User · Answer

There is a library available for getting hardware specific informations  Hardware serial number extractor  CPU  RAM  HDD  BIOS

User · Answer

What about just using the UniqueID of the processor

User · Answer

Can you pull some kind of manufacturer serial number or service tag   Our shop is a Dell shop  so we use the service tag which is unique to each machine to identify them   I know it can be queried from the BIOS  at least in Linux  but I don t know offhand how to do it in Windows

User · Answer

With our licensing tool we consider the following components   MAC Address CPU  Not the serial number  but the actual CPU profile like stepping and model  System Drive Serial Number  Not Volume Label  Memory CD-ROM model  amp  vendor Video Card model  amp  vendor IDE Controller SCSI Controller   However  rather than just hashing the components and creating a pass fail system  we create a comparable fingerprint that can be used to determine how different two machine profiles are  If the difference rating is above a specified tolerance then ask the user to activate again    We ve found over the last 8 years in use with hundreds of thousands of end-user installs that this combination works well to provide a reliably unique machine id - even for virtual machines and cloned OS installs

User · Answer

I hate to be the guy who says   you re just doing it wrong   I always hate that guy    but     Does it have to be repeatably generated for the unique machine  Could you just assign the identifier or do a public private key  Maybe if you could generate and store the value  you could access it from both OS installs on the same disk   You ve probably explored these options and they doesn t work for you  but if not  it s something to consider   If it s not a matter of user trust  you could just use MAC addresses

User · Answer

Look up CPUID for one option  There might be some issues with multi-CPU systems

User · Answer

Why not use the MAC address of your network card

User · Answer

I had an additional constraint  I was using  net express so I couldn t use the standard hardware query mechanism  So I decided to use power shell to do the query  The full code looks like this   Private Function GetUUID   As String     Dim GetDiskUUID As String    get-wmiobject Win32 ComputerSystemProduct    Select-Object -ExpandProperty UUID      Dim X As String          Dim oProcess As New Process       Dim oStartInfo As New ProcessStartInfo  powershell exe   GetDiskUUID      oStartInfo UseShellExecute   False     oStartInfo RedirectStandardInput   True     oStartInfo RedirectStandardOutput   True     oStartInfo CreateNoWindow   True     oProcess StartInfo   oStartInfo     oProcess Start       oProcess WaitForExit       X   oProcess StandardOutput ReadToEnd     Return X Trim   End Function

User · Answer

What about just using the UniqueID of the processor

User · Answer

Try this one  it gives a unique hard disk ID  Port of DiskId32 for Delphi 7-2010

User · Answer

Look up CPUID for one option  There might be some issues with multi-CPU systems

User · Answer

Parse the SMBIOS yourself and hash it to an arbitrary length  See the PDF specification for all SMBIOS structures available   To query the SMBIOS info from Windows you could use EnumSystemFirmwareEntries  EnumSystemFirmwareTables and GetSystemFirmwareTable   IIRC  the  unique id  from the CPUID instruction is deprecated from P3 and newer

User · Answer

Maybe cheating a little  but the MAC Address of a machines Ethernet adapter rarely changes without the motherboard changing these days

User · Answer

Can you pull some kind of manufacturer serial number or service tag   Our shop is a Dell shop  so we use the service tag which is unique to each machine to identify them   I know it can be queried from the BIOS  at least in Linux  but I don t know offhand how to do it in Windows

User · Answer

I hate to be the guy who says   you re just doing it wrong   I always hate that guy    but     Does it have to be repeatably generated for the unique machine  Could you just assign the identifier or do a public private key  Maybe if you could generate and store the value  you could access it from both OS installs on the same disk   You ve probably explored these options and they doesn t work for you  but if not  it s something to consider   If it s not a matter of user trust  you could just use MAC addresses

User · Answer

In my program I first check for Terminal Server and use the WTSClientHardwareId  Else the MAC address of the local PC should be adequate   If you really want to use the list of properties you provided leave out things like Name and DriverVersion  Clockspeed  etc  since it s possibly OS dependent  Try outputting the same info on both operating systems and leave out that which differs between

User · Answer

Maybe cheating a little  but the MAC Address of a machines Ethernet adapter rarely changes without the motherboard changing these days

User · Answer

I had the same problem and after a little research I decided the best would be to read MachineGuid in registry key HKEY LOCAL MACHINE SOFTWARE Microsoft Cryptography  as  Agnus suggested  It is generated during OS installation and won t change unless you make another fresh OS install  Depending on the OS version it may contain the network adapter MAC address embedded  plus some other numbers  including random   or a pseudorandom number  the later for newer OS versions  after XP SP2  I believe  but not sure   If it s a pseudorandom theoretically it can be forged - if two machines have the same initial state  including real time clock  In practice  this will be rare  but be aware if you expect it to be a base for security that can be attacked by hardcore hackers   Of course a registry entry can also be easily changed by anyone to forge a machine GUID  but what I found is that this would disrupt normal operation of so many components of Windows that in most cases no regular user would do it  again  watch out for hardcore hackers

User · Answer

Why not use the MAC address of your network card

User · Answer

Can you pull some kind of manufacturer serial number or service tag   Our shop is a Dell shop  so we use the service tag which is unique to each machine to identify them   I know it can be queried from the BIOS  at least in Linux  but I don t know offhand how to do it in Windows

User · Answer

What about just using the UniqueID of the processor

User · Answer

Maybe cheating a little  but the MAC Address of a machines Ethernet adapter rarely changes without the motherboard changing these days

User · Answer

I had the same problem and after a little research I decided the best would be to read MachineGuid in registry key HKEY LOCAL MACHINE SOFTWARE Microsoft Cryptography  as  Agnus suggested  It is generated during OS installation and won t change unless you make another fresh OS install  Depending on the OS version it may contain the network adapter MAC address embedded  plus some other numbers  including random   or a pseudorandom number  the later for newer OS versions  after XP SP2  I believe  but not sure   If it s a pseudorandom theoretically it can be forged - if two machines have the same initial state  including real time clock  In practice  this will be rare  but be aware if you expect it to be a base for security that can be attacked by hardcore hackers   Of course a registry entry can also be easily changed by anyone to forge a machine GUID  but what I found is that this would disrupt normal operation of so many components of Windows that in most cases no regular user would do it  again  watch out for hardcore hackers

User · Answer

Parse the SMBIOS yourself and hash it to an arbitrary length  See the PDF specification for all SMBIOS structures available   To query the SMBIOS info from Windows you could use EnumSystemFirmwareEntries  EnumSystemFirmwareTables and GetSystemFirmwareTable   IIRC  the  unique id  from the CPUID instruction is deprecated from P3 and newer

User · Answer

Can you pull some kind of manufacturer serial number or service tag   Our shop is a Dell shop  so we use the service tag which is unique to each machine to identify them   I know it can be queried from the BIOS  at least in Linux  but I don t know offhand how to do it in Windows

User · Answer

Look up CPUID for one option  There might be some issues with multi-CPU systems

User · Answer

In my program I first check for Terminal Server and use the WTSClientHardwareId  Else the MAC address of the local PC should be adequate   If you really want to use the list of properties you provided leave out things like Name and DriverVersion  Clockspeed  etc  since it s possibly OS dependent  Try outputting the same info on both operating systems and leave out that which differs between

User · Answer

You should look into using the MAC address on the network card  if it exists   Those are usually unique but can be fabricated  I ve used software that generates its license file based on your network adapter MAC address  so it s considered a fairly reliable way to distinguish between computers

User · Answer

There is a library available for getting hardware specific informations  Hardware serial number extractor  CPU  RAM  HDD  BIOS

User · Answer

Why not use the MAC address of your network card

User · Answer

I had an additional constraint  I was using  net express so I couldn t use the standard hardware query mechanism  So I decided to use power shell to do the query  The full code looks like this   Private Function GetUUID   As String     Dim GetDiskUUID As String    get-wmiobject Win32 ComputerSystemProduct    Select-Object -ExpandProperty UUID      Dim X As String          Dim oProcess As New Process       Dim oStartInfo As New ProcessStartInfo  powershell exe   GetDiskUUID      oStartInfo UseShellExecute   False     oStartInfo RedirectStandardInput   True     oStartInfo RedirectStandardOutput   True     oStartInfo CreateNoWindow   True     oProcess StartInfo   oStartInfo     oProcess Start       oProcess WaitForExit       X   oProcess StandardOutput ReadToEnd     Return X Trim   End Function

User · Answer

Try this one  it gives a unique hard disk ID  Port of DiskId32 for Delphi 7-2010

User · Answer

What about just using the UniqueID of the processor

User · Answer

With our licensing tool we consider the following components   MAC Address CPU  Not the serial number  but the actual CPU profile like stepping and model  System Drive Serial Number  Not Volume Label  Memory CD-ROM model  amp  vendor Video Card model  amp  vendor IDE Controller SCSI Controller   However  rather than just hashing the components and creating a pass fail system  we create a comparable fingerprint that can be used to determine how different two machine profiles are  If the difference rating is above a specified tolerance then ask the user to activate again    We ve found over the last 8 years in use with hundreds of thousands of end-user installs that this combination works well to provide a reliably unique machine id - even for virtual machines and cloned OS installs

User · Answer

You should look into using the MAC address on the network card  if it exists   Those are usually unique but can be fabricated  I ve used software that generates its license file based on your network adapter MAC address  so it s considered a fairly reliable way to distinguish between computers

User · Answer

Look up CPUID for one option  There might be some issues with multi-CPU systems

User · Answer

For one of my applications  I either use the computer name if it is non-domain computer  or the domain machine account SID for domain computers  Mark Russinovich talks about it in this blog post  Machine SID      The final case where SID duplication would be an issue is if a distributed application used machine SIDs to uniquely identify computers  No Microsoft software does so and using the machine SID in that way doesn   t work just for the fact that all DC   s have the same machine SID  Software that relies on unique computer identities either uses computer names or computer Domain SIDs  the SID of the computer accounts in the Domain      You can access the domain machine account SID via LDAP or System DirectoryServices

User · Answer

You should look into using the MAC address on the network card  if it exists   Those are usually unique but can be fabricated  I ve used software that generates its license file based on your network adapter MAC address  so it s considered a fairly reliable way to distinguish between computers

User · Answer

I hate to be the guy who says   you re just doing it wrong   I always hate that guy    but     Does it have to be repeatably generated for the unique machine  Could you just assign the identifier or do a public private key  Maybe if you could generate and store the value  you could access it from both OS installs on the same disk   You ve probably explored these options and they doesn t work for you  but if not  it s something to consider   If it s not a matter of user trust  you could just use MAC addresses

User · Answer

I hate to be the guy who says   you re just doing it wrong   I always hate that guy    but     Does it have to be repeatably generated for the unique machine  Could you just assign the identifier or do a public private key  Maybe if you could generate and store the value  you could access it from both OS installs on the same disk   You ve probably explored these options and they doesn t work for you  but if not  it s something to consider   If it s not a matter of user trust  you could just use MAC addresses

User · Answer

In my program I first check for Terminal Server and use the WTSClientHardwareId  Else the MAC address of the local PC should be adequate   If you really want to use the list of properties you provided leave out things like Name and DriverVersion  Clockspeed  etc  since it s possibly OS dependent  Try outputting the same info on both operating systems and leave out that which differs between

User · Answer

In my program I first check for Terminal Server and use the WTSClientHardwareId  Else the MAC address of the local PC should be adequate   If you really want to use the list of properties you provided leave out things like Name and DriverVersion  Clockspeed  etc  since it s possibly OS dependent  Try outputting the same info on both operating systems and leave out that which differs between

[windows] Generating a unique machine id

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