Unknown devices

Dell XPS 13 9343

I have now downgraded to Windows 7 and installed all drivers. Everything works fine, but there are three unknown devices which I cannot detect. There is a "Other devices" branch in the device manager, and in this branch there are tree "unknown devices". I've tried to look for the missing drivers at Dell site using their support assistant, but to no avail. I have installed all possible drivers from the Dell website. I have looked for these devices/drivers with the Driver Detective, but it was not able to detect what is missing.

Any idea what is that?