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How to: Use SOS

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Visual Basic




Web Developer


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SOS is an external component you can use to debug managed applications and view their dump files.

To use SOS, you must first load the SOS extension into the debugger by using the Immediate Window. You can then type commands and view output in the Immediate window. SOS does not use any other debugger windows, such as the Call Stack or Locals windows.

To debug a managed application by using SOS, you must attach the debugger in both native mode and managed mode. For more information, see SOS.dll (SOS Debugging Extension), or see the following page on the Microsoft Web site: SOS: It's Not Just an ABBA Song Anymore.

To load the SOS debugger extension

  1. Open the dump file.

    For more information, see How to: Save and Open Dump Files.

  2. On the Debug menu, click Start and wait for the execution to break.

  3. In the Immediate window, type the following command:

    .load sos

    If the Immediate window cannot find SOS, you might have to specify the full path, which is:


    The version of SOS must match the version of the common language runtime that is used in the dump file.

To get SOS command Help

  1. After SOS is loaded, in the Immediate window, type the following command:


  2. For more specific information about a command, type:

    !help command

To stop an SOS command

  • On the Debug menu, click Stop Evaluation.