device-factory-reset.md

Device Factory Reset

A Device Factory Reset re-applies a pre-stored Windows image (from the recovery partition) to the OS partition. It also allows the clearing of the TPM.

The Device Factory Reset operation is initiated by either:

• The application calling DeviceManagementClient.StartFactoryResetAsync().
• The application calling DeviceManagement.StartFactoryResetAsync().
• The operator invoking the Azure direct method windows.startFactoryResetAsync.

DeviceManagementClient.StartFactoryResetAsync()

    Namespace:
	Microsoft.Devices.Management

    Class:
    DeviceManagementClient

    Methods:
    public async Task StartFactoryResetAsync(bool clearTPM, string recoveryPartitionGUID)

Notes:

• DeviceManagementClient.StartFactoryResetAsync() requires a connection to IoT Hub and it will update the device twin with its status.

Example

    async Task OnRebootClicked(DeviceManagementClient dmClient)
    {
        await dmClient.StartFactoryResetAsync(true, "<recoveryPartitionGUID>");
    }

DeviceManagement.StartFactoryResetAsync()

    Namespace:
	Microsoft.Devices.Management

    Class:
    DeviceManagement

    Methods:
    public async Task StartFactoryResetAsync(bool clearTPM, string recoveryPartitionGUID)

Notes:

• DeviceManagement.StartFactoryResetAsync() does not require a connection to IoT Hub and it will not update the device twin with its status.

Example

    async Task OnRebootClicked(DeviceManagementClient dmClient)
    {
        DeviceManagement dm = DeviceManagement.CreateWithoutAzure();
        await dm.StartFactoryResetAsync(true, "<recoveryPartitionGUID>");
    }

windows.startFactoryResetAsync

This interface is asynchronous and will return before completing the operation. The status can be tracked through the device twin factoryReset node (see below).

Input Payload

{
    "recoveryPartitionGUID" : "recoveryPartitionGuid"
    "clearTPM" : "see below"
}

• "recoveryPartitionGUID" : This is the guid of the partition that contains the Windows image file (wim) to be re-applied.
• "clearTPM" : When set to "true", all TPM slots will be cleared - otherwise, TPM will be not be cleared.

Output Payload

windows.startFactoryResetAsync returns a Status Object (see Status Reporting).

{
    "status" : {
        <Status Object>
    }
}

For details on Status Object, see Error Reporting.

Device Twin Reporting

As the method executes, it will also update the device twin with its current status and its final state.

"reported" : {
    "windows" : {
        "factoryReset": {
            "lastChange" = <Status Object>
        }
    }
}

Example

Input

{
    "recoveryPartitionGUID" : ""66F49469-6F65-4E1D-9891-2EB2E83C8B85""
    "clearTPM" : "true"
}

Output

{
    "status" : {
        "time" : "time stamp",
        "state": "pending",
    }
}

Device Twin Reporting

"reported" : {
    "windows" : {
        "factoryReset": {
            "lastChange": {
                "time" : "time stamp",
                "state": "pending"
            }
        }
    }
}

And then, upon success, it will be changed to:

"reported" : {
    "windows" : {
        "factoryReset": {
            "lastChange": {
                "time" : "time stamp",
                "state": "completed"
            }
        }
    }
}

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