It seems that newer UEFI BIOSes from Dell now prevent you from MBR-booting from the internal hard disk (e.g. SATA, PCIe NVMe or M.2). However, you can still configure the BIOS to MBR-boot from external boot devices such as USB drives.
Details can be found on Dell Support link.
So, you can boot to the E2B grub4dos MBR boot menu (or MBR boot from a Rufus or other MBR USB drive) and install Windows 10 to the internal hard disk, however, when you reboot from the internal hard disk, you will see a 'No boot device found' error because the BIOS will only allow you to boot via UEFI from internal disks.
It seems that some of these Dell BIOSes were strictly UEFI-only at first, but then Dell released newer versions of the BIOS which included the 'Legacy External Devices' option. So you may need to update the BIOS if your current Dell BIOS does not have this option.
I suspect Dell later realised that a lot of their support utilities which relied on booting from USB or PXE only worked in MBR mode and so had to add this BIOS option!
Disclaimer: I don't actually have one of these systems to experiment with, so this information is just gleaned from the linked articles.
Details can be found on Dell Support link.
So, you can boot to the E2B grub4dos MBR boot menu (or MBR boot from a Rufus or other MBR USB drive) and install Windows 10 to the internal hard disk, however, when you reboot from the internal hard disk, you will see a 'No boot device found' error because the BIOS will only allow you to boot via UEFI from internal disks.
It seems that some of these Dell BIOSes were strictly UEFI-only at first, but then Dell released newer versions of the BIOS which included the 'Legacy External Devices' option. So you may need to update the BIOS if your current Dell BIOS does not have this option.
I suspect Dell later realised that a lot of their support utilities which relied on booting from USB or PXE only worked in MBR mode and so had to add this BIOS option!
Disclaimer: I don't actually have one of these systems to experiment with, so this information is just gleaned from the linked articles.