Can't find the option to disable secure boot in BIOS

Question

I have a ThinkCentre M82p. I'm trying to install Ubuntu but it keeps saying OS not found regardless of what I do (installed fresh ubuntu, startup-repair from live cd, even tried a new drive), secure boot seems to be the culprit. I just can't find the option to disable it.

It's usually under security or startup correct? http://i.imgur.com/uzo6WJs.jpg

Though if secure boot was the issue wouldn't it prevent me from booting from ubuntu live usb in the first place, let alone install it?

Solution

First, I'm not sure your computer even uses an EFI; it might be a pure-BIOS system. I say this because this CNET page notes that it originally shipped with Windows 7. Although some machines, shipped late in the Windows 7 period, did come with EFIs, most systems that shipped with Windows 7 used a regular BIOS. Of course, the CNET page might be wrong, or your computer might have shipped with an EFI and Windows 7.

Second, many early EFI-based systems lacked Secure Boot support. Thus, even if you've got an EFI-based computer, you might not find any Secure Boot options.

Third, where Secure Boot options appear varies greatly -- although they sometimes appear on the "Security" tab, where you're looking, they're as likely to appear on the "Boot" tab or somewhere else. See this page of mine for several examples of how to disable Secure Boot. I can't promise your firmware settings will look exactly like any of those in my examples; in fact, I can almost promise that yours won't be an exact match to any of them. With any luck, though, yours will be at least similar to one that I've shown. (Assuming it really is an EFI-based system with Secure Boot support, not a BIOS-based one or an EFI-based computer without Secure Boot.)

Fourth, it's not clear to me why you think you're running into a Secure Boot issue. Ubuntu does support Secure Boot, and should install without problems, or even any extra hoop-jumping, on most computers with Secure Boot active. (There are exceptions to this rule, because of bugs in specific computers' implementations and other issues, but for the most part Ubuntu's Secure Boot support does work.) In particular, it sounds as if you've booted the installer, run it, and then get an error message when you reboot. If this is accurate, it's almost certainly not Secure Boot that's causing the problems, since a Secure Boot problem would have prevented you from booting the computer.

Chances are something else is causing you problems. This could be related to the Compatibility Support Module (CSM) on an EFI-based computer. See this page of mine for information on how a CSM can create problems. Alternatively, if you've got a BIOS-only computer, it could be that something has gone wrong when installing the BIOS-mode version of GRUB. To provide us with better information, please run the Boot Info Script. This will generate a file called RESULTS.txt. Post that file to a pastebin site and post the URL to your document here. This will give us more details about your configuration, which is required to base an answer on more than guesswork.

Comments

[M. Becerra]

Please run dmidecode | less and edit your question with the output.

[VidathD]

Is this your first time installing Ubuntu? If so, what is your current OS?