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.
I ran into one of these pain-in-the-rear systems a few months ago at work when we bought a hardware refresh for some of our field service engineers. We use an MBR booting image so that it can be deployed to any system, then on UEFI capable systems I wrote a script which is deployed alongside the image which automates use of the Windows built in MBR2GPT tool to convert it to UEFI booting system when supported. But of course, since Dell stopped allowing the OS to MBR boot, my usual imaging process wouldn't work here. And fixing it wasn't as easy as it probably should have been...
ReplyDeleteFun fact, the Dell BIOS doesn't expose the M.2 SSD to booted OSes unless you have your drive mode set to AHCI instead of "RAID ON" under your system settings in BIOS.
So what I did was restore the MBR image, set drive to AHCI, and UEFI boot to the Windows install disc (thanks E2B and imgPTN!), then try to run MBR2GPT from the boot disc. Unfortunately MBR2GPT wouldn't detect my MBR image as a convertible one and would fail. So alternate methods were needed. Ultimately, I ended up having to re-restore the image with the drive set in AHCI mode, then use information in this tutorial to manually do what MBR2GPT would normally do automatically:
https://social.technet.microsoft.com/wiki/contents/articles/14286.converting-windows-bios-installation-to-uefi.aspx
Dell caused quite a headache for me with this change - made me start preparing a UEFI version of my image going forward so I don't run into this again next time we buy hardware. Hopefully my info helps someone experiencing the same trouble though!