We have several different models of Dells in our environment and I have KMDF and UMDF both installed in our base Windows 7 image.
We are using the Latitude E8 (A18) driver family pack for our Windows 7 x64 image. We have several Latitude E7470 laptops with the NVME M2 drives in them and they OK. But we only have a few of the E7270 laptops and we can't get any of them to load.
It applies the OS and loads drivers and when it reboots, it starts to install the drivers and then it blue screens on the iastora.sys (PAGE_FAULT_IN_NONPAGED_AREA) and then when it reboots, it comes up with the screen below and never goes any further. This is the same symptom that you have when you don't have KMDF and UMDF or NVME support installed... and I know we have it installed, because we've been through this with the E7470s.