Windows 10: No boot device found for cloned SSD on external USB drive

Both flash drives I used were formatted as FAT32. I checked in Disk Management and it shows the only partition as being "Healthy (Active, Primary Partition)" so I don't think this is the problem.

 

You are correct. The Dell Latitude E7470 is set to RAID. However, my new M.2 PCIe drive works. I did install Windows 10---just have not been able to do a data migration or use Reflect to clone my old SSD to the new. So, I have re-loaded software and data files. Not a big deal, but....I should have been able to do a cloning exercise!

Coincidentally, I did try changing the setting to both ACHI and to disable SATA (the only two other setting offered). Neither setting would allow me to boot up, though, so I went back to the RAID setting. The reason I tried disabling RAID is that I have been unable to install the Samsung driver---get a message that "NVM Express Device not connected" when I execute the driver file. Samsung's Driver Manual states that Windows cannot load the driver where "PCH Storage Configuration is set to "Raid Mode..." So, I am using a very dated Windows driver for the Samsung. All seems to work OK, but I am not getting the advertised speeds. Ran Crystal Mark and got only 1,786 seq read and 1,531 write. Not bad for writing, but about half what I should be getting in read speeds. I suspect the driver is the issue, but so far haven't been able to sort this out.

 

To see how the drive is running, check the Device Manager and look at Storage Controllers. If it shows a SATA device the drive is not running using the NVME controller.

To change from RAID to AHCI, if your system will run it, use the old method. Open msconfig.exe and set the system to boot into Safe Mode.

Reboot and go into the Bios and change SATA to AHCI. Let the system reboot back into Safe Mode.

Open msconfig.exe again and set the boot to normal and verify the checkmark on Safe Boot has been removed, then reboot.

If the system supports the PCIe drive, it should work.

Many folks seem to be able to load Windows on a PCIe drive but it will not boot afterward. The PCIe driver needs to be in the Bios. Dell just told users of the Inspiron 7567 gaming the PCIe driver was not compatible with the Samsung 960 Pro or EVO. And it was confirmed when someone tried a NVME version of the SM951, which worked normally.

You won't get advertised speeds since the system is not a dedicated PCIe M.2 slot.

 

Yes. Device Manager Storage Controllers shows an "Intel Chipset SATA RAID Controller" (and a Microsoft Storage Spaces Controller). I'll try changing to the AHCI using msconfig. Didn't work when I changed it in the Bios---wouldn't boot.

 

OK, this worked! Now booting into AHCI, and the Samsung driver loaded. No improvement in speed, though! Still 1,777 read and 1,527 write. Not sure if the M.2 slot is dedicated or not. I think the SSD is the only PCIe device on the laptop. But...maybe Dell is only using two channels instead to the four? Not sure about this either---if the motherboard only has 2 channels it seems to me that the write speed would be affected as much as read, and that is not the case here.