PnPUtil.exe cannot enumerate devices with Extension class

Question

PnPUtil.exe cannot enumerate devices with Extension class

guliteb 41

PnPUtil.exe cannot enumerate devices of Extension class.

PnPUtil.exe /enum-devices /class Extension or pnputil.exe /enum-interfaces /class {e2f84ce7-8efa-411c-aa69-97454ca4cb57} returned 'No devices were found on the system.'

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Answer 1

Zac Lockard 116 Microsoft Employee

Extension is not a device class, no devices can have that class. INFs can be the class 'extension', which specifically means it is not the device class or main driver for the device, but instead contains supplemental operations for the main driver.

guliteb 41 Reputation points

2021-04-07T01:49:03.907+00:00

Is there any way to enumerate all installed extension INFs and its related driver information? Currently, I can only see extension INFs as below:
Zac Lockard 116 Reputation points Microsoft Employee

2021-04-07T01:52:33.213+00:00

There's pnputil /enum-drivers but we don't have a way to scope that to just extensions currently
Castorix31 90,686 Reputation points

2021-04-07T04:53:37.23+00:00

Extension is not a device class

It is listed at System-Defined Device Setup Classes Available to Vendors

Extension INF
Class = Extension
ClassGuid = {e2f84ce7-8efa-411c-aa69-97454ca4cb57}
(Windows 10 and later versions of Windows) This class includes all devices requiring customizations. For more details, see Using an Extension INF File.
guliteb 41 Reputation points

2021-04-07T06:21:16.297+00:00

I would like to understand how the 'Extension Driver Names' are enumerated and tied to the base driver as the result captured above.
Zac Lockard 116 Reputation points Microsoft Employee

2021-04-07T20:53:11.393+00:00

It's a class for the sake of install (setup), but a device cannot receive this class. It's reserved to mean that it extends whatever primary INF is being installed on the device, where the device's class is ultimately the class of the primary INF.
Zac Lockard 116 Reputation points Microsoft Employee

2021-04-07T20:57:37.543+00:00

They're treated just like any other driver, right up until the point of installation. When they're added to the system, they get an oemxx.inf name that is just numbered sequentially based on the order added to the system. Then, they're matched on devices using the exact same HWID/compat ID matching that main drivers use.

More details: https://learn.microsoft.com/en-us/windows-hardware/drivers/install/using-an-extension-inf-file

Answer 2

Castorix31 90,686

Did you check if you get them with PowerShell, like :

Get-PnpDevice -Class 'Extension'

guliteb 41 Reputation points

2021-04-05T03:08:32.613+00:00

It did not work.

Thanks.

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PnPUtil.exe cannot enumerate devices with Extension class

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