I would advise installing the samsung NVME drivers BEFORE trying to install the drive.   NVMe™ Driver   NVMe™ Driver Installation Guide * Notice : The driver applies to Windows 7, Windows 8.1 and Windows 10. 
I recently bought XPS 8940 with HDD from Dell outlet and I'm looking to add SAMSUNG 980 PRO 1TB PCIe NVMe Gen4 Internal Gaming SSD M.2. Does anyone know if XPS 8940 would take advantage of the SAMSUNG 980 PRO speeds? This is what Samsung told me but I wanted to confirm. "Based on the specs provided by Dell the 980 PRO would be compatible. However based on the specs provided, the system only supports up to PCIe gen 3x4, the drive would perform up to gen 3 and not at gen 4 as advertised.
XPS 8940 adding SAMSUNG 980 PRO 1TB PCIe NVMe Gen4 Internal SSD M.2