I have an ASUS PN40 mini PC that I have set up for Home Assistant. It works well except for the fact that it has a built in 32Gb EMMC chip as a hard drive - which is turning out to be a bit small in size for using Windows10. I have successfully added a 256Gb SSD which is recognised by Windows but I cannot disable the EMMC chip to allow the SSD to be the primary HDD.
I’ve tried ASUS support but they have not been of much use unfortunately.
looking at the website, PN40 dont have any options for storage with 32gb emmc, the smallest it can be installed is 128gb nvme storage. and you can also install a 2.5inch sata drive on it, I assume you installed a 256gb SATA SSD. hence you got two drives.
still, just look deep inside the unit and look for the nvme slot, if you see something is plugged on the nvme slot, that’s probably your emmc storage.