[ Thanks to James Maguire for this
link. ]
“One near foolproof approach is to run with a dedicated Linux
PC. Not a practical solution for everyone, but a solid option
nonetheless.“The second approach might be to make a disk image of your
Windows installation. This way if the dual-booting setup goes wrong
and repairing the MBR doesn’t help due to the partitioning being
done improperly, the end user is not totally out of luck trying to
recover their Windows files.”