Accessing a 3rd HDD under grub

["Chuckk Hubbard" <badmuthahubbard@gmail.com>]

Hi.
A friend's computer died, and she'd like to retrieve her files.
Before setting up my dual-boot system this would have been a piece of
cake.  Now, though, if I replace the Windows drive, it can't boot, and
if I replace the Linux drive it reads the MBR but can't reach the GRUB
options.
Is there a way to temporarily deactivate GRUB's changes to the MBR, so
I can boot from my Windows drive and access a different slave HDD?

Thanks.
Chuckk

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