Create a Bootable CD or DVD with InfraRecorder

A bootable disc carries, in addition to its files, a boot image that a computer’s firmware can load before any operating system starts — the mechanism behind rescue discs, installers and diagnostic tools. InfraRecorder 0.53 supports creating bootable data discs using the El Torito standard, which is the boot specification used by CDs and DVDs. The burn itself is easy; the part people get wrong is the boot image. A folder of files, however complete, is not bootable unless a valid boot image is included and correctly configured — this guide explains the requirements and walks through the process.

You need InfraRecorder 0.53 from the download page, a blank CD or DVD, the files for your disc, and a suitable boot image. InfraRecorder is free under GPL v3, written for the Windows 2000 to Windows 7 era — which matters here, because El Torito booting belongs to the legacy BIOS world, as explained below. The program itself is not officially supported on Windows 10 or 11, though it generally runs there; see InfraRecorder on Windows 11 for those notes. The age of the target machine matters more than the age of the machine doing the burning.

What Makes a Disc Bootable: El Torito and the Boot Image

Under the El Torito specification, the disc contains a boot catalogue and one or more boot images. When a compatible computer starts from the disc, the firmware reads the catalogue, loads the boot image as if it were a floppy disk or hard disk, and hands control to it. The boot image is therefore a real, bootable system in miniature — historically a floppy-disk image containing DOS or a loader, or a hard-disk image, or a “no emulation” image that loads its own code directly, which is how most operating system installers work. InfraRecorder’s part in this is to embed the boot image you supply, with the emulation and load settings you choose, into the project it burns. It cannot create a boot image from ordinary files, and it cannot make a non-bootable set of files bootable by ticking a box.

Where do boot images come from? Typically from the same place as the files they boot: the publisher of a rescue tool or operating system supplies either a ready-made bootable ISO — which needs no work at all, just the image-burning process — or a boot image file to use in a project like this one. You can also extract the boot image from an existing bootable disc or floppy, but modifying an image’s boot parameters without understanding its loader is the fastest route to a disc that boots to a black screen.

A Necessary Note on BIOS, UEFI and Modern Machines

El Torito booting is a legacy BIOS mechanism. Computers from the era InfraRecorder was written for boot from it directly. Modern machines use UEFI firmware: many still offer a legacy or CSM (Compatibility Support Module) mode that can boot El Torito discs, but some have dropped legacy booting entirely, and Secure Boot can also refuse unsigned boot images. Practically: a bootable disc you make with this guide is intended for older, BIOS-based machines and for UEFI machines with legacy mode enabled. Do not expect it to start a modern UEFI-only laptop, and do not blame the burn when it does not — test on the class of machine the disc is actually for. For modern installer media, the publisher’s own ready-made ISO, burned as an image, is almost always the correct route.

Step by Step: Building the Bootable Disc

1. Gather the contents. Collect the files that belong on the disc and the boot image file in known folders. Decide the disc’s file system as InfraRecorder’s project options present it — UDF and ISO 9660/Joliet are the filesystems it supports — keeping in mind the boot image itself sits outside the normal file area.
2. Insert a blank disc in the burner. A CD is enough for most rescue and DOS-era tools; use a DVD when the file set is large.
3. Open InfraRecorder and start a data project. Bootable discs begin as data projects; the boot configuration is added through the project’s properties.
4. Add the files. Add all the ordinary files and folders that should be visible on the finished disc, arranged as their programs expect to find them.
5. Open the project properties and find the boot settings. In the advanced/bootable options for the project, enable the bootable-disc option. This is the step that turns a data project into an El Torito disc.
6. Point to the boot image. Select the boot image file you prepared. Then set the emulation mode to match that image: floppy emulation for a floppy image (in the size the image was made for), hard-disk emulation for a hard-disk image, or no emulation when the image’s own documentation says so — most modern installer loaders use no emulation. Mismatched emulation is the most common reason a correctly burned disc refuses to boot.
7. Check load settings if offered. If the project exposes load segment or sector-count settings, leave them at their defaults unless the boot image’s documentation specifies values — the defaults suit standard images, and an installer ISO’s own parameters are already correct in the ready-made-image route.
8. Check the capacity meter so files plus boot structures fit the inserted media, then confirm the recorder.
9. Set a moderate write speed and burn. Bootable discs earn their keep on bad days; burn them carefully, with verification enabled where offered, and close/finalise the disc — use a single session rather than leaving it open for multisession additions, because boot discs should be finished, self-contained media. Session behaviour is explained in the multisession guide.
10. Test on a suitable machine. Boot the target-class (BIOS or legacy-mode) computer from the disc: set the optical drive first in the boot order or use the boot-menu key, and confirm the disc starts its loader. Testing is not optional — an untested boot disc is just a data disc with ambitions.

If the Disc Will Not Boot

Work through the causes in order: the machine is UEFI-only or legacy mode is off (change the firmware setting or use a suitable machine); the disc is not first in the boot order (use the boot menu); the emulation mode does not match the boot image (reburn with the correct mode); or the boot image itself is not bootable (return to its source — InfraRecorder cannot repair it). A disc that boots on one older machine but not another modern one has usually demonstrated that it works; the difference is firmware, not the burn.

Related Guides

If your source is a finished bootable ISO, skip project-building entirely and burn the ISO as an image — its boot structure is already embedded. To preserve a bootable disc you already own, imaging it to ISO keeps its boot information intact, and copying it via an image reproduces it faithfully.