I made a new Marcium USB Rescue Disk. I changed the boot order for the usb to be first. In setup (F12), I also changed from UEFI Secure to Legacy. I tried it both ways. Neither worked. Dell XPS 9370 Bios 1.13.1. Windows 10.

Make sure your Rescue Media was built using WinRE or WinPE 4 or above.  The version is indicated at the top of the Rescue Media Builder interface.  In that case, you do not need to switch from UEFI to Legacy, nor should you.  Same goes for mucking around with the boot order  Set the system back to UEFI with Secure Boot enabled, then use the F12 one-time boot menu to manually select your flash drive as the boot device.  That will override the standard boot order just for that single boot event, saving you having to rearrange the boot order to just to boot from USB when temporarily needed, then go back and change it back later.  If you don't see your flash drive listed in the F12 menu even though it was connected before you powered your system on, then maybe try another brand of flash drive.  Also make sure you're actually using a flash drive, not a hard drive or SSD.  Some systems don't support booting from USB "removable storage class" devices like most flash drives, and not "fixed disk class" devices like hard drives and SSDs.

"...Same goes for mucking around with the boot order..."  One reason for establishing booting order such as: USB flash drive[s], CD/DVD device, then internal HDD or SSD -- easier to boot and access rescue media if suddenly the internal drive does not function or Windows fails to load.  Other than that, I agree that boot order need not be changed.

"Take care of thy backups and thy restores shall take care of thee."  Ben Franklin revisited.

+x

 

Roland Stoller - 30 March 2021 8:50 PM

"...Same goes for mucking around with the boot order..."  One reason for establishing booting order such as: USB flash drive[s], CD/DVD device, then internal HDD or SSD -- easier to boot and access rescue media if suddenly the internal drive does not function or Windows fails to load.

And one HAZARD of putting a "special case" boot device higher in your system's boot order is that you might end up accidentally booting into that environment, e.g. if you happened to leave your Rescue Media flash drive plugged in after you updated it.  That can especially be a problem if for example you had restarted your PC remotely and expected it to come back up so that you could connect to it remotely afterward, which now wouldn't be possible because your PC would now be sitting in your Rescue environment rather than having reloaded Windows.  Another hazard is that an attacker could get your PC to boot an arbitrary environment on a USB device, although closing that off would require setting a BIOS password.

While it's true that not everyone reboots their PC remotely and needs to reconnect remotely afterward, sudden OS or drive failures aren't exactly commonplace either.  In any case, I don't think the convenience of not having to press a one-time boot menu key when you very occasionally want to boot from USB is worth risking the inconvenience of accidental boots from USB devices in the meantime.  If that happened even once, you'd lose more time on that incorrect boot cycle than you'd ever save by not having to press that one-time boot menu key when you actually wanted to boot from USB.

@RolandJS I kind of disagree, thing is altering boot order from default (Windows/HDD first) wastes time on a standard boot/reboot, add up routine boots, & not only does the cumulative effect waste time on routine boots, but also decreases security, since any random bootable USB/DVD (even unintentionally bootable) causes machines to boot from potentially infected boot media.

I was at school, in a hurry to finish up.  I should have been clear.  Of course in any open business or open home environs - you two are absolutely correct!  I was thinking in a home environs, like mine, two laptops by themselves and nobody else has access (unless they break in carrying ready-made usb sticks) in there, I prefer having externals listed before internals.

"Take care of thy backups and thy restores shall take care of thee."  Ben Franklin revisited.