The command was executed properly, but now the issue is different, the device isn't found at all. Could you open
Device Manager (for example right-click on Start), and check if there's a
Movidius MyriadX under
Universal Serial Bus devices. It should appear immediately when the OAK device is connected, before running the DepthAI demo app.
If it's not possible to get it detected by disconnecting and connecting again, please try rebooting the PC.