A boot disk is a type of removable media like a floppy disk, CD, DVD or USB drive that contains software used to startup or “boot” a computer. Boot disks allow you to boot a computer into a different operating system or access diagnostic tools outside of the primary OS installed on the hard drive.
Boot disks used to be quite common, especially with older computers in the 1990s and early 2000s that came with floppy disk drives. However, their necessity and usage has declined significantly over the years as other boot options have become available.
When would you need a boot disk today?
There are a few scenarios where you may still find a boot disk useful even with modern computers:
- Recovering data from a computer with a corrupted operating system. Booting from a separate disk allows you to access the hard drive without loading the damaged OS.
- Diagnosing and troubleshooting computer problems. Boot disks give you access to various diagnostic and repair tools.
- Installing or reinstalling an operating system. You can install something like Linux from a Live CD/USB boot disk.
- Accessing your files and data from a computer that won’t boot. Boot to an external drive to backup or transfer files.
- Increased security when conducting sensitive work on a shared or untrusted computer. Boot your own secure OS from removable media without using the installed HDD.
- Booting on machines that don’t have an OS installed yet. This includes new builds or devices that don’t ship with an operating system.
In these types of situations, having a dedicated boot disk on hand can make recovering data, troubleshooting problems, reinstalling an OS or accessing your files much easier when you can’t boot from the primary hard drive.
What are the alternatives to boot disks today?
There are now quite a few ways to startup or boot a computer beyond traditional removable media like floppy/optical discs and USB drives:
- Bootable flash drives – USB flash drives that are much faster, higher capacity and more reliable than old floppy discs.
- External hard drives or SSDs – Booting from a USB external drive provides even more space for boot files and diagnostics.
- Network booting – Technologies like PXE allow booting over a network instead of locally from a disk.
- Bootable CD/DVD drives – While less common today, optical discs can still work as boot media.
- Boot manager – Modern UEFI systems include a boot manager to select boot devices and files.
- OS recovery partitions – Restoring Windows, macOS and other OSs is now done through built-in recovery partitions.
The most common and practical options are using a bootable USB flash drive or external SSD. These provide faster performance and more storage space for boot files than legacy floppy or optical discs. They plug into any computer’s USB port making them convenient and portable.
Do you still need optical discs?
While booting from USB drives has become more popular, there can still be some benefit to maintaining optical disc boot media:
- Discs are read-only, so malware cannot infect the boot files.
- No need to locate or carry USB drives; discs are easy to store and find.
- Works on older systems limited to booting from optical drives only.
- CDs and DVDs are incredibly cheap to produce.
However, USB drives have some notable advantages over optical media:
- Faster read/write speeds, especially with USB 3.0+.
- Rewritable and erasable unlike ‘burned’ CD/DVDs.
- More capacity for boot files and diagnostics tools.
- Supported for booting on nearly all modern PCs.
While CD/DVD boot discs can still be useful in some situations, USB drives provide better convenience, capacity and compatibility for most use cases today.
How to make a bootable USB drive
Making your own bootable USB drive is easy and offers a great way to access recovery tools or run another OS on any PC. Here’s a quick overview of how to create one:
- Get a USB flash drive with at least 4GB of capacity. Higher capacity drives provide more room for boot files and tools.
- Download the ISO file for the bootable OS or software you want. Examples include Windows installation media, Linux live CDs, diagnostics tools like UBCD or Parted Magic, etc.
- Use bootable USB creator software to write the ISO to your flash drive. Examples include Rufus on Windows or Startup Disk Creator on Mac/Linux.
- Configure your computer’s UEFI or BIOS settings to enable booting from your USB drive first before the HDD.
- Boot up your PC with the USB drive inserted. It will load the operating system or tools from the flash drive instead of the HDD.
Once created, label your USB drive clearly so you remember it’s purpose. Store it in a safe place you can easily access when needed for recovery or diagnostic tasks.
Creating a DOS boot disk
MS-DOS boot floppies used to be common for maintenance tasks, but making a DOS boot disk today is more complicated since most modern machines no longer support booting to floppy discs. However, you can create bootable DOS USB drives instead using these steps:
- Get DOS files – Legally obtain DOS system files from an old disc or ISO. DOS is obsolete so avoid piracy.
- Make USB bootable – Use Rufus or similar software to make your USB drive bootable.
- Add DOS files – Copy the DOS system files over to the root of your bootable USB drive.
- Use boot options – Your UEFI or BIOS may need specific settings to boot USB drives or legacy OSs.
- Boot from USB – Restart your computer and boot from the USB to load DOS.
This will let you access DOS tools from a modern PC. However, many diagnostic and repair tools now have far more capable modern replacements making DOS limited today.
Creating a multi-boot USB drive
Rather than booting just a single OS or program, you can also create a USB drive with multiple bootable options using these steps:
- Use a large drive – A 16GB+ USB drive provides enough space for multiple OSs and tools.
- Partition the drive – Use Disk Management or GParted to create partitions for each OS.
- Make partitions active – Set each partition boot flag to “active” for bootability.
- Install boot files – Copy or extract the bootable OS files into their respective partitions.
- Configure boot manager – Install a boot manager like GRUB2 to manage the boot options.
- Select boot option – Pick the desired system to launch when booting from the drive.
This allows you to carry multiple bootable systems and tools on a single USB drive. However, the process is more complex than creating a single-boot device.
Recommended boot disk tools
Here are some of the most useful boot disks and tools to create for diagnostics and system recovery:
| Boot Disk | Description |
|---|---|
| Windows Installer | Official Windows 10/11 installer for reinstalling or recovery. |
| Clonezilla | Disk imaging and cloning for backup/restore. |
| GParted | Partition manager for creating, resizing, formatting drives. |
| Memtest86+ | Memory tester to check for RAM errors or failures. |
| Linux Live CD | Booting Linux even when Windows won’t load. |
| Network Boot Disk | Recovery tools with the ability to PXE boot from a network. |
Having at least the Windows or Linux media, drive cloning tools and diagnostics like Memtest86+ provides a great starting point for most troubleshooting and recovery needs.
Creating a network boot disk
Network booting allows a client to boot over a network connection from a remote server using the PXE protocol and boot images. This allows recovery and troubleshooting even if the local system is unbootable. Here is how to create a PXE network boot environment:
- DHCP Server – Configure a DHCP server to provide IP addresses and PXE boot options.
- TFTP Server – Set up a TFTP server to host the boot files the clients will load.
- Boot Images – Add your bootable OS or tool ISO files to the TFTP server directory.
- Client Setup – Enable PXE boot support in the BIOS/UEFI firmware settings.
- Network Boot – Clients will now PXE boot from the server remotely.
This allows you to boot multiple systems from centralized, network-accessible boot images for convenient maintenance.
Choosing the right boot method
With multiple boot options available, which method is right for you depends on these factors:
- System support – Older systems may only allow legacy boot devices.
- OS/tool needs – Boot requirements like UEFI vs. BIOS, 32-bit vs 64-bit.
- Network availability – PXE network booting requires DHCP and TFTP servers.
- Use frequency – How often boot media is needed to justify cost and complexity.
- Physical access – Local boot if hardware access is limited or remote if unrestricted.
- Security – Network or optical discs provide read-only boot images.
For occasional use on modern hardware, a simple USB drive offers the best combination of performance, ease-of-use and compatibility for most users’ needs.
Conclusion
While boot disks are less critical in the age of hard drive OS recovery partitions, USB bootable drives still offer a quick way to access diagnostic tools or recover data from a failed computer. USB flash drives provide better performance and capacity than old floppy or optical discs.
Creating a basic boot drive with your OS installer, some disk and memory diagnostics like Memtest86+, and data recovery tools like Clonezilla provides an essential toolkit. Include any other systems or tools you need for work or recovery processes. Just be sure to store your boot drive in a safe place you can easily access when needed.
Understanding your boot options saves you time and hassle when you need to recover or troubleshoot a failed system. With bootable USB drives, you can easily carry your toolbox anywhere without relying on old floppy or optical media. When computer problems strike, the right boot disk helps you get back up and running again quickly.
