Cannot Access UEFI

usquebaugh

Prominent
Feb 17, 2017
2
0
520
So I recently made the mistake of installing windows 10 and have been attempting to set my computer up for dual booting a linux OS as I have done under 7 and XP previously. However I cannot access the UEFI. Hitting "Restart for UEFI Settings" under advanced boot options simply reboots the computer and pushes me back to the windows 10 login screen, hammering at my bios access button during this boot does not change anything. Shift + Restart does not access the recovery options, though shutdown.exe /r /o manages to. Booting the drive I want to install directly results in a black screen and no GRUB long after one would expect to see one. BOOT.ini appears to have been deprecated and so changing that no longer appears to be a fix.

My setup is as follows:
ASUS Z170-AR
Windows installed on an M.2 SSD

Any sugestions would be great, windows 10 appears to be utterly dedicated to keeping my hands away from any options or settings that I might want to change.
 
Solution


Wrong forum. Nothing to do with opensource software...
Read your motherboard manual. Disable secure boot. Do not enable Legacy boot unless you want to reinstall windows too.
On page 54 is the BIOS chapter. Press [DELETE] just after power-on to unter bios/uefi settings. If you cannot get into BIOS then you are just not pressing at the right time.
 

usquebaugh

Prominent
Feb 17, 2017
2
0
520


No idea how this got here, I posted it on the windows 10 forum. Long story short was that the windows fast boot had limited the timeframe for pressing del to less than the time it took for the screen to render the bios logo. Disabling fastboot from within windows 10 failed to actually disable fast boot, so the solution was to physically remove the SSD that windows was installed on and reboot. The live USBs were not being detected due to ASUS only allowing UEFI boot if the bootloader matches some windows verification code (other operating systems are considered to be "unauthorised". For now I've set the CSM/UEFI to "auto" which allows me to boot any linux operating systems in legacy mode while windows in UEFI, though this causes GRUB2 to fail. For a longer term solution I need to add the linux bootloader codes to the list of allowed and then presumably reinstall using UEFI rather than Legacy.

Having installed linux on a separate drive, it did not override the windows bootloader.
 
Solution