I want to do is change the default boot menu from:
VGA=791 to VGA=773 and SLEEP=10 to SLEEP=0

Using ImgBurn for Windows and ISO master for Linux.

I've changed the following files:
changed /menu.lst, /grub4dos.lst, /boot/isolinux/isolinux.cfg, /boot/syslinux/suslinux.cfg.

No matter what is changed, it either fails to boot or constant rebooting. I see the correct info, if I do 'e' on the grub4dos boot up menu.

Solved. I needed to rebuild the iso using mkisofs. In the past this wasn't needed.