Bootable Discs
When you burn a Data disc to CD, DVD or Blu-ray it is possible to make them bootable, so that if they are loaded in your computer when it is powered on then your computer will boot from the disc instead of from the computers hard drive. This is commonly used for your operating system install discs, recovery discs and similar cases.
Express Burn can create such discs given two things;

1. The disc must contain all the needed files to boot, which is basically a fully bootable operating system. These file are included on your install discs and vary considerably between operating systems. Please check online resources for further details on what files to add.
2. The boot sectors. These are an image of a small section of a bootable disc. A number of utilities can extract these, and they can be found commonly using internet searches. These also vary considerably by the operating system you are using. A suggested utility is Roadkil's Boot Builder http://www.roadkil.net/program.php?ProgramID=3

When you have both of these you can use Express Burn to burn the bootable disc. Just add the operating system files and folders to your disc and then burn the disc. In Burn Settings click 'Advanced' and select that the disc is bootable and select your file of boot sectors.
NOTE: If you are burning an ISO image then you do not need to do any of this, the boot sectors and operating system will be included in the image.
NOTE: You cannot boot from a pure UDF disc. If you set these options, the disc will be converted to a hybrid disc to ensure it can be booted.