Why won’t Windows auto-install built-in drivers like disk.inf or usbstor.inf (e.g. USB flash drives)?

I recently ran into a persistent issue on my Windows 10 22H2 (Build 19045.6093) machine where plugging in USB flash drives and external drives would no longer automatically install the required built-in (“inbox”) drivers.

Symptoms:

• In Device Manager: “USB Mass Storage Device” node appeared fine, but the disk drive underneath had a yellow exclamation mark (Code 28: no compatible driver found).
• disk.inf was present in C:WindowsINF and in the DriverStore, but automatic installation wouldn’t work,
• Similar issue appeared for devices that might use usbstor.inf or uaspstor.inf.

I tried:

• Checking Group Policy (no restrictions).
• Running sfc /scannow and DISM /RestoreHealth (they didn’t do anything useful),
• Verifying installed drivers via pnputil and Get-WmiObject Win32_PnPSignedDriver (drivers missing from listings).
• Manually staging drivers, which worked but required tedious effort and didn’t persist reliably.