This happened to me yesterday as I uninstalled all Nvidia programs in programs files ( I wanted to clean up old files and reg). I didn't use DDU but maybe this helps none the less. I did disable WU so it couldn't DL and install the driver. I first uninstalled HD audio and PhysX which needed a reboot on each to clear, then I did display driver and again rebooted. After about 30sec before I could install new driver I see windows installed drivers, but if you looked at program files nothing shown, but Device manager does, so I installed new drivers and then check DiverStoreExplore and I see 2 entries for NV, one with "Nv_dispi.inf" and one "nv_dispiwu.inf" and I think the last is from WU and that was what it installed. I do clean out old ones but being the naming is different DiverSoreexplorer doesn't mark it as old, guess should have removed that one first. Anyway, though it might help others I normally never run into this and guess most user either if you just use NV installer.