MS-DOS not being added to GRUB menu

[Liam Proven]

I have installed beta 1 of Lubuntu 12.04 on an old PC I'm planning to give away.

The only thing that is not flawless about it is that GRUB2 has not
picked up that the primary partition on hard disk 0 contains MS-DOS -
7.1, specifically, from a Windows 98SE recovery floppy. It's a small
install - just the core utils in a \DOS directory - but when I run
`update-grub` it appears not to notice it at all.

Is there any way of manually adding an OS to GRUB2?

-- 
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