Boot From a Disc to Start Diagnostic, Setup, and Other Offline Tools
You might have to boot from a CD, DVD, or BD to run certain kinds of testing or diagnostic tools, like memory testing programs, password recovery tools, or bootable antivirus software.
You also might need to boot from a disc if you’re planning to reinstall the Windows operating system or run automatic Windows repair tools.
When you boot from a disc, what you’re actually doing is running your computer with whatever small operating system that’s installed on the CD, DVD, or BD.
When you start your computer normally, you’re running with the operating system installed on your hard drive, like Windows, Linux, etc.
Follow these really easy steps to boot from a disc, a process that usually takes around 5 minutes:
Tip: Booting from a disc is operating system independent, meaning that booting from a CD or DVD in Windows 7 is the same as in Windows 10, or Windows 8, etc.
How To Boot From a CD, DVD, or BD Disc
1. Change the boot order in BIOS so the CD, DVD, or BD drive is listed first. Some computers are already configured this way but many are not.
If the optical drive is not first in the boot order, your PC will start “normally” (i.e. boot from your hard drive) without even looking at what might be in your disc drive.
Note: After setting your optical drive as the first boot device in BIOS, your computer will check that drive for a bootable disc each time your computer starts. Leaving your PC configured this way shouldn’t cause problems unless you plan on leaving a disc in the drive all the time.
Tip: See Booting From a flash drive instead of this tutorial if what you’re really after is configuring your PC to boot from a flash drive or other USB storage device. The process is fairly similar to booting from a disc but there are a few extra things to consider.
2. Insert your bootable CD, DVD, or BD in your disc drive.
How do you know if a disc is bootable? The easiest way to find out if a disc is bootable is to insert it into your drive and follow the remainder of these instructions. Most operating system setup CDs and DVDs are bootable, as are many advanced diagnostic tools like the ones I discussed above.
Note: Programs downloadable from the internet that is intended to be bootable discs are usually made available in ISO format. See How To Burn an ISO File for more on that. (Hint: You can’t just burn the ISO image to the disc like you can other files.)
3. Restart your computer – either properly from within Windows or via your reset or power button if you’re still in the BIOS menu.
4. Then watch out for “Press any key to boot from CD or DVD” … message.
When booting from a Windows setup disc, and occasionally other bootable discs as well, you may be prompted with a message to press a key to boot from the disc. For the disc boot to be successful, you’ll need to do this during the few seconds that the message is on the screen.
If you do nothing, your computer will check for boot information on the next boot device in the list in BIOS (see Step 1) which will probably be your hard drive.
Most bootable discs do not prompt for a key press and will start immediately.
5. Your computer should then boot from the CD, DVD, or BD disc.
Note: What happens now depends on what the bootable disc was for. If you’re booting from a Windows 10 DVD, the Windows 10 setup process will begin. If you’re booting from a Slackware Live CD, the version of the Slackware Linux operating system you’ve included on the CD will run. You get the idea.