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Your computer will be set to boot from various locations in a certain order. To boot from a disc, you set the boot order in the BIOS.

Hi, Leo. I just purchased Macrium Reflect, Version 5, and I did as you explained in your newsletter last week. It was an excellent explanation to install, make a rescue disc, and then image backup. After I created the rescue disc, I tried to check to see if it will boot the computer in case of a system problem. I found out that Windows starts as normal; not using the rescue disc. How do I turn the DVD drive on to boot from the rescue disc? Thanks very much.

In this excerpt from Answercast #17, I explain how to set your BIOS to boot from a rescue disc.

Turn DVD drive on to boot?

So, it's not that you need to turn the DVD drive on, and in fact, it's not a change you make in Windows at all. The boot process happens before Windows is even loaded.

What you need to do is make a change to a BIOS setting.

BIOS is software that is built into your computer that helps the computer understand how to boot. It's the software that you see on your screen immediately after you turn the machine on. It may run a memory test. It may tell you some version information about the machine, some amount of memory you have, some hardware information – those kinds of things.

Those tests are all performed by software that is a physically part of the machine, whether or not you have a hard disk installed, much less Windows.

Enter the BIOS before booting

What you need to do is: at boot time, press the key sequence or the "key" that causes the BIOS to enter its settings editing mode.

Now, I have to say the "key" because I don't know what the key is for your computer.

Typically, there will be a message on the screen that says, "Press something to change settings" or "For settings" or something like that:

  • It could be any one of the function keys, F1 through 12.
  • It could be Delete.
  • It can be a couple of other keys I've seen randomly used.

Pay attention to what that key is. Look for it as you reboot your machine next time.

Press that key before the boot process actually begins and the BIOS will enter a settings mode – a mode where you can make some fundamental changes to your system settings, to your BIOS settings.

Boot order

One of the settings may be called the "Boot Order" or the "Boot Priority." Again, the terminology varies from BIOS to BIOS.

Also, where it will appear in the settings will vary from one machine to another. So I can't really point you specifically where to look.

The concept is the BIOS (when it tries to boot) will check the hardware that's installed on your machine in a particular order. For example:

  • In the days of floppy discs, the BIOS would check the floppy disc to see if there was a disc inserted, and if there was, it would try to boot from that before it even looked at the hard disk.

  • If there was no floppy disc, it would look at the hard disk.

  • Nowadays, we actually have several different kind of alternatives for booting. We can be looking at the hard disk; we could be looking at a CD; we could be looking at an attached USB device.

But the difference is that the BIOS needs to know which one to check first.

In your case, it sounds like the BIOS is checking the hard disk first and since it's finding a bootable operating system on the hard disk, that's what it runs with.

Set CD/DVD as priority boot

Without checking anything else, the BIOS setting that you change actually instructs the BIOS to check the CD drive or your DVD drive first before it checks the hard drive.

  • If you don't have a DVD installed, actually inserted in the drive, it doesn't matter. The check is very quick. It immediately moves on and checks the hard drive.

  • But if you do then have a bootable CD inserted into the drive (as you would with a restoration disc), then the BIOS will begin to boot from that without even looking at the hard drive.

So that's the thing you need to look for; that's the thing you need to change.

I'm sorry I can't give you more specifics on exactly where to find it on your machine, but that is how you get your machine to begin to boot from a CD that's been installed.

Article C5336 - May 14, 2012 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

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6 Comments
John
May 15, 2012 12:05 PM

This is not so much a comment as a question. Should I have my BIOS set to check a CD or DVD drive first before it tries to boot from the hard drive? I asked this so that if the hard drive is dead it will try the CD drawer for another bootable medium. Does anyone have an answer? If it doesn't find a hard drive to boot from or finds a dead one, would it automatically check for bootable media in the optical drive drawer, or must I set the BIOS accordingly?

Mark J
May 15, 2012 12:59 PM

@John
I have my BIOS set to check first for an OS on my optical drive CD/DVD. That way if I put in a bootable disc, it will boot from that, otherwise it will boot from my hard drive. If the hard drive is is dead, depending on the computer and how dead the hard drive, it may or may not then look for an OS on the optical drive. So generally, it's not a bad idea to have the BIOS set to boot first from the CD/DVD drive.

Russ
May 15, 2012 1:15 PM

John, You should commonly have your BIOS set to check the CD or DVD drive first before it tries to boot from the hard drive. If there is no bootable CD or DVD in the drive, the computer will go ahead and boot from the hard drive. This way, you have a choice even if there still is a usable hard drive.

John Servis
May 17, 2012 9:34 PM

@John, I agree with Russ & Mark.

To the original poster of the question, To find out which key to use in order to gain access to the boot order in your Bios on your particular machine, you could go to your manufacturer's support page and search for the boot order settings key under Bios related information for your model number or just simply Google "boot order Bios settings key" or something along those lines for your make & model#.
The info you need to gain access will flash across the very top, or very bottom of the screen at start up, but default factory settings usually are so very fast, it's hard to catch first time. Sometimes the settings to display boot info are set not to display at all!
Googling the info is probably the fastest way to find out.
Once you figure that out, you have to click or (High-lite) "boot from CD/DVD/Optical Drive & move it up the list of options with the up arrow in order to make it the first out of all the boot options. Hope some of this helps you out. J.

John
May 22, 2012 8:53 PM

Thanks everybody for your help and comments. I am not a total neophyte, but some things have you eluded me. Again thanks for helping.John J.

Bill Landau
May 23, 2012 3:05 PM

Some computers - Dell is an example I am familiar with - have a key to change boot order on the fly. With Dell, it is F12. If you hit F12 before the Windows splash screen appears, you'll be asked which medium to boot from.

Also, on many computers, even if CD/DVD is set as the first boot medium, if the boot process finds a disc in the drive, the prompt Strike any key to boot from CD/DVD... will appear, and if you ignore it, your computer will still boot from the hard drive (or USB, or whatever is next in the boot order).

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