*I am trying to recover files for a friend from a Dell Inspiron15 5000 Series laptop. Windows 10 is installed and won’t boot.
Normally this would not be a problem. I would simply boot Linux from a USB pen drive and copy the files to an external USB hard drive. Once the files were safely copied to external media, I’d try fixing the O/S, or, as a last resort, re-installing from the factory partition.
If I had trouble accessing the disk, I would query the disk’s microcontroller with smartctl to find out if there’s a disk error causing the problem.
If so, I would boot SeaGate’s SeaTools software, which on past occasions has successfully recovered seemingly unusable hard disks (by forcing the disk’s microcontroller to re-map bad sectors). In the past, I’ve used this technique successfully to make a hard disk usable long enough to recover files.
This machine has “UEFI secure boot” enabled in the BIOS. I’ve never dealt with this before.
When I press F2 on power-up to get into the BIOS, there is an option to “Change BOOT mode” to “Legacy Boot Mode, Secure Boot Off”… but when I select that I get an ominous warning that it might make the disk unreadable.
Having never dealt with UEFI Secure Boot before, I want to proceed very cautiously since it’s not my machine.
So my question is, are there any gurus out there who have personal experience with turning UEF off so you can boot removable media? Is it safe to do? Are there any precautions I should be aware of? I don’t trust Microsoft.