How to Create an Exclusion List for Unknown Computer Support

Applies To: System Center Configuration Manager 2007 R2, System Center Configuration Manager 2007 R3

Unknown computer support is an operating system deployment feature in Configuration Manager 2007 R2 that allows unmanaged systems to be discovered and receive operating system deployment. The exclusion list provides a list of computer MAC addresses to which the PXE server should not send task sequences to install an operating system. PXE requests from computers whose MAC addresses appear on the exclusion list will be ignored by the PXE server.


The information in this topic applies only to Configuration Manager 2007 R2 and Configuration Manager 2007 R3.

How to create an exclusion list for unknown computer support

  1. Create a new text file on the PXE site server. Name the file appropriately—for example, exceptions.txt.

  2. Using a standard text-editing program such as Notepad, edit the new text file to add the MAC addresses of computers to be ignored by the PXE server. The MAC address elements should be separated by colons and each MAC address should be on a separate line. For example, 01:23:45:67:89:ab. Save and close the exception list file.

  3. Edit the registry of the PXE site server to create a MACIgnoreListFile registry key that contains the string value of the full path to the location of the text file on the PXE site server.

    • 32-bit server: HKLM\Software\Microsoft\SMS\PXE

    • 64-bit server: HKLM\Software\Wow6432Node\Microsoft\SMS\PXE

See Also


About Unknown Computer Support for Operating System Deployment

For additional information, see Configuration Manager 2007 Information and Support.
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