I thought I had succeeded in setting up a dual-boot machine, but —
Booting 'Windows XP' rootnoverify(hd0,4) chainloader +1
and it stops there. Hanh?
Oh well, better that than the other way around (Windows but no Linux).
Much later: Lei at GigaBox told me that Red Hat’s partitioner wrecks the boot block that Windows needs; I should try again, using the Windows setup to partition the disk.