Once you’ve downloaded Berry, you have to burn it to a CD. In fact, the ISO file you downloaded from this site is a complete image of the CD. It won’t work if you burnt the iso just like a regular file, so start your favourite CD-writing software and find „Burn image“ or „Burn CD iso image“ option. It could be hidden somewhere because people usually don’t need to use this option. Sometimes you will need to change the file-type filter to *.* else you won’t be able to see your .iso. Check the programs help files if you can’t find the option. The resulting CD will be bootable, you don’t need to specify that feature separately.

Note: Some archiving software (for example winrar) could associate the .iso extension for itself. It seems like berry.iso would be an compressed archive. But don’t believe this. Don’t unpack the archive! burn the ISO as described above else you will lose the bootability.

See http://www.petri.co.il/how_to_write_iso_files_to_cd.htm

How to add my boot options

If the screen of GRUB is displayed, type ‚e‘. Then the choise screen of kernel
is displayed and type ‚e‘ again. Then you can add options like ‚vga=773‘ at the end of line.