re: Dual-booting F7 and WinXP on separate harddisks

> Bought a new 320 GB EIDE disk and installed it as MASTER and moved the
> previous MASTER (a 160 GB EIDE disk that booted WinXP) to SLAVE. That
> made the old hd0 hd1 and the new disk hd0. Without any OS installed on

> the new hd0, the machine continued to boot WinXP from hd1.

Are you sure of this above? No change at all, and swap from master to slave of the previous disk? Did you change anything in BIOS options?

perhaps it would help if inside windows section of grub you have something like this:

title Other
	rootnoverify (hd1,0)
        map (hd1) (hd0)
        map (hd0) (hd1)
	chainloader +1

HIH,
Gianluca