0

My notebook (HP ProBook 650) is currently set to boot in Legacy mode in BIOS. In this mode, Win7 were installed, and later Win10 on a second disk (so there is some sort of multi-boot for these two, but I have no idea how it works).

I would like to be able to boot some UEFI OS from external drive as well, so I was going to change the BIOS setting to Hybrid boot mode. In my understanding, this should ensure that the "old" OS (Win7 & Win10 on internal HDD) could be still booted in legacy mode, and at the same time UEFI OS could be booted from external disk.

But there was a warning in BIOS saying that this change could "adversely affect" the ability to boot current OS.

So how serious are they? Is it just a plain warning "just in a case", or can this change really corrupt the current Windows bootloader?
What is the correct procedure to change to Hybrid boot, minimizing the risk the current system will boot no more?

Thanks for advice.

Improve this question
2
  • 1
    They don't say it will corrupt anything, they say you may not be able to boot after changing it. If it doesn't boot after changing it, just change it back... If you're worried, make a full backup first.
    – Ƭᴇcʜιᴇ007
    Mar 22, 2018 at 16:52
  • Windows 10 is 100% compatible with Legacy Mode. If you install Windows while in UEFI mode, you cannot enabled, Legacy Mode. Windows will not boot. Meanwhile Windows installed in Legacy mode while in UEFI will not be bootable
    – Ramhound
    Mar 22, 2018 at 22:44

1 Answer 1

Reset to default
0

Yes, it's safe and shouldn't affect actual installations in anyway.

BUT, i need to be sure to select boot device from boot menu. This could be done thru boot menu, as one of boot devices would be external drive i dont recommend. I prefer do it manually. (normally F9, F10, F11 or F12 buttons, check what fits your system).

Improve this answer
2
  • Thanks, I can confirm everything is working as expected.
    – Plzak
    Mar 23, 2018 at 13:03
  • The boot order is of course important, but there are limitations as to what can be set in BIOS - in particular, there is a separate priority list for booting in Legacy mode, and a separate list for UEFI boot order. It seems that the UEFI list is taken as the first one, and only if it fails, the Legacy list is used. So even if I prioritized the internal HDD in both lists, if an external UEFI boot drive is connected, it is booted first, as the internal disk uses Legacy boot. But this is OFT, just for information.
    – Plzak
    Mar 23, 2018 at 13:12

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .