Can't disable secure boot
 

Hi, I'm pretty new to linux so I'm sorry if this is a dumb question, but I really can't find an answer anywhere else, I've been looking for over a week now.
I have an ASUS X556UB laptop, I've formatted the drive to get rid of the windows it came with, and installed Ubuntu Gnome.
However, I'm having trouble getting the machine to use the dedicated graphics card (GTX 940M).
It seems the problem is that I haven't disabled secure boot. The option is greyed out and unselectable in the BIOS, even though I've set admin and user passwords in the security tab.
Can anyone help, should I reformat and start from scratch with another OS? This is the third one I've tried, it's like this laptop is just allergic to linux.
It took me hours and hours to sort all the other problems out, this looks like the last thing. Any help would be greatly appreciated :)

How to Disable or Enable Secure Boot on Your Computer via ASUS UEFI BIOS Utilityhttps://www.technorms.com/45538/disa...i-bios-utility

Disable ASUS Motherboard's UEFI secure boot

Asus VivoBook X556UB

Hello and welcome to LQ.

If you installed Ubuntu (good job!) then secure boot will have nothing to do with graphics issue. I assume it is greyed out is because you also disabled UEFI. You didn't really need to on LTS. Side note. Uefi presents hardware. I assume the uefi and legacy will both present internal video card.

So, what do you mean about this graphic card? Why do you say it isn't working?

What lead you to that conclusion ?.
Post a link to a reference.

Thanks for the replies.
It seems though that the computer has decided on its own that it does want to use the graphics card.
I haven't touched it in a few days, but after booting it not only says nvidia prime is now supported (this was the problem before), but that it booted into using the dedicated graphics automatically.

Very strange. It's like the computer fairies came in the night and fixed it for me.
Would still like to be able to disable secure boot though. The laptop came with Aptio Setup Utility.

Hi...

Glad it's working now. If you would, please mark this thread as "SOLVED" by clicking on "Thread Tools" directly above your initial post. Thanks! :)

Regards...