If you have at least one FAT16 / FAT32 partition you can always use a DOS boot diskette, but having a DOS / Win9x hard drive partition + Boot Magic is certainly easier (once it's set up).
Edit: <rant> MS spends billions to cram more bundled bloatware and monopolyware down our throats but doesn't have the decency to spend $50-100K to build a good "DOS + VGA emulator with MoSlo" app for XP so we can keep playing X-Com, Wing Commander, etc. etc. </rant>