OK, well you've probably had to to do this fewer times than me, and you won't ever need to do it again anyway.*
Trust me, it's the easiest way to hit a bootloader, boot into linux and restore the mbr after xp nuked it... if your mb is not usb-bootable, like mine.
Saves faffing around with tedious slow boot from a live disk, and chroots.
It's true the boot floppy could die in the meantime, but it's a doddle to recreate (best to test it first though).
*unless you need to resq gran's old pc. Oh wait, gran's vey unlikely to have a dual boot with linux. Never mind.
EDITED: 20 Jul 2015 19:04 by DSMITHHFX