Boot from CD/DVD ROM: Step-by-Step Setup

Booting your computer from a CD or DVD is useful when you need to install an operating system, run a recovery tool, or use a live Linux environment. This guide walks you through changing the boot order in your system’s BIOS or UEFI firmware so your optical drive is checked before the hard drive at startup. You’ll need your computer, the bootable disc, and a few minutes to access the setup utility.

What You’ll Need

A bootable CD or DVD (e.g., OS installer, recovery disc)
Your computer’s power cord (if it’s a desktop, keep it plugged in during BIOS access)
Knowledge of your motherboard or manufacturer’s BIOS key (common keys: F2, F12, Del, Esc)
Optional: A USB keyboard if your current keyboard isn’t recognized in BIOS

Step-by-Step

Insert the disc: Place the bootable CD/DVD into your optical drive. If your drive is a tray type, close it gently. For slot-loading drives, push the disc in until it pulls itself.
Restart or power on: If your computer is already on, save your work and restart. If it’s off, press the power button. Immediately begin tapping the BIOS key (usually F2, F12, Del, or Esc) about once per second until the BIOS/UEFI setup screen appears. The key is often shown briefly on the splash screen.
Navigate to boot options: Once in BIOS, look for a tab or menu labeled “Boot,” “Boot Order,” “Boot Options,” or “Startup.” Use the arrow keys to move around. On some UEFI systems, you may need to click with a mouse.
Change the boot order: Find the list of boot devices (e.g., Hard Drive, USB, CD/DVD, Network). Highlight “CD/DVD” or “Optical Drive” and move it to the top of the list. The method varies: on many systems, you press + or – to move items; on others, you press Enter and select from a menu. Look for on-screen instructions.
Enable legacy boot (if needed): If your disc is not UEFI-compatible (e.g., an older Windows installer), you may need to enable “Legacy Boot” or “CSM” (Compatibility Support Module) in the BIOS. This is often under the “Boot” or “Security” tab. If you see “UEFI” vs “Legacy” options, choose Legacy for older discs.
Save and exit: Press the key indicated for “Save and Exit” (usually F10). Confirm that you want to save changes. Your computer will restart.
Wait for the prompt: As the computer restarts, watch for a message like “Press any key to boot from CD or DVD.” If you see it, press any key quickly (you have about 5 seconds). If you miss it, the computer will boot from the hard drive; simply restart and try again.

Common Mistakes

Not pressing the BIOS key in time: Tapping the key too early or too late can cause you to miss the setup. Start tapping immediately when the screen goes black, not after the logo appears.
Wrong BIOS key: Using the wrong key for your manufacturer (e.g., F2 instead of F12) won’t open BIOS. Check your manual or the splash screen text.
Disc not bootable: Not all discs are bootable. A data CD or a movie DVD won’t boot. Ensure the disc was burned as a bootable image (e.g., .iso file) or is an original installer disc.
Changing the wrong setting: Altering other BIOS settings (like CPU settings) can cause instability. Only change the boot order and related boot options.
Forgetting to save: If you exit without saving, your changes are lost. Always use the “Save and Exit” option.

Tips

Use the one-time boot menu: Many systems allow you to press a key (often F12, F11, or Esc) at startup to bring up a temporary boot device menu. This lets you select the optical drive once without changing the default order permanently.
Keep the disc in the drive: If you plan to reinstall, keep the disc in until the process completes. Removing it early can cause errors.
Verify the disc: If the disc is scratched or burned poorly, it may fail to boot. Try a different disc if possible.
Update firmware: If your BIOS is very old, it might not recognize newer discs. Check your manufacturer’s site for updates, but only if you’re comfortable with the process.

Troubleshooting

Computer boots to hard drive anyway: Re-enter BIOS and confirm the optical drive is first. Also check that the disc is properly inserted and that it’s actually bootable. If using a UEFI system, try enabling Legacy Boot/CSM.
“Press any key” prompt doesn’t appear: This prompt may be hidden if the disc is not bootable or if the boot order is wrong. Try a known-good bootable disc (like a Linux live CD) to test.
BIOS doesn’t show the optical drive: Check the SATA or IDE cable connection inside the desktop. For laptops, ensure the drive is properly seated. Also check if the drive is disabled in the BIOS under “SATA Configuration.”
System freezes during boot from disc: This can be due to a scratched disc or a failing optical drive. Try cleaning the disc with a soft cloth, or use a different drive. If the disc is fine, consider creating a bootable USB instead.
UEFI vs Legacy confusion: If your disc is for an older OS, it may not work with UEFI mode. Switch to Legacy/CSM in BIOS. Conversely, if you’re installing a modern 64-bit OS, keep UEFI enabled.

Frequently Asked Questions

Why won’t my computer boot from the CD even though it’s first in the boot order?

Most likely the disc isn’t bootable. Check that it contains a bootable operating system or utility. Also, if the disc is scratched or dirty, the drive may fail to read it. Try a different disc or clean the current one.

What is the difference between UEFI and Legacy boot?

UEFI is the modern firmware standard that supports large hard drives, faster boot, and secure boot. Legacy (or CSM) is the older BIOS mode that is compatible with 32-bit operating systems and older discs. Some discs only work in one mode.

Can I boot from a DVD-RW or CD-RW?

Yes, as long as the disc has been properly finalized and contains a bootable image. Rewritable discs are fine, but they can be less reliable than pressed discs.

How do I create a bootable CD from an ISO file?

You need disc-burning software that can “burn image” or “write ISO.” In Windows, you can right-click an ISO and select “Burn disc image.” On macOS, use Disk Utility. The software will create a bootable disc automatically.

Will booting from a CD erase my hard drive?

No, booting from a CD just runs the disc’s program. It won’t erase anything unless you explicitly choose to install or format during that program. For example, an OS installer will ask before partitioning.

How do I change back to boot from hard drive after using the CD?

Simply remove the disc and restart. If you changed the boot order permanently, you can re-enter BIOS and move the hard drive back to the top, or use the one-time boot menu to select the hard drive.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

More in this bed

The whole Tech How-To bed →