How can I check whether an ISO image is bootable?

On Windows, how can I check whether an ISO image is bootable, without writing it to a DVD or running it on virtual machine?

Don't forget the command line tool file.

$ file /cygdrive/t/test.iso clonezilla-live-1.2.12-60-amd64.iso
/cygdrive/t/test.iso:                # ISO 9660 CD-ROM filesystem data 'CDROM                           '
clonezilla-live-1.2.12-60-amd64.iso: # ISO 9660 CD-ROM filesystem data '1.2.12-60-amd64                 ' (bootable)

If the ISO image is bootable, there will be a "(bootable)" string at the end of line of file command output. (You may want to scroll to the right of code snippet above if there is horizontal scroll bar in it. I've rewritten the CSS for this site using Stylish addon in Firefox browser, so I don't have a scroll bar in it)

You can install Cygwin or the standalone file package of GnuWin32 (looks like no active development anymore) to get file tool for Windows. For linux system, in most linux live cds, the file command is in there.

Open the file to browse the content with a software which can open and browse ISO content. Use WinRAR or MagicISO ISO Explorer and see there are boot files present.

I recommend MagicISO which will indicate an ISO as Bootable or Non-Bootable