I've got a single-board computer and when I connect Intel 18260NGW using PCI he identify it as an "unknow device" and accordingly WiFi on my computer doesn't works. I was trying to solve this problem by installing Intel PROSet/Wireless WiFi Software (includes drivers) for Windows 10 but it didn't help.
We understand your recently installed Intel® Tri-Band Wireless-AC 18260 is being identified as an Unknown Device.
We recommend to manually install the latest wireless driver only, please follow these steps to do so:
If this resolves your issue, or you have more question on the subject, please let us know. For us to provide additional suggestions, we may need the report created using thehttps://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility Intel® System Support Utility.
We are just checking on this post. Please let us know if you had the chance to manually install the driver for your wireless adapter.