bootcamp sudden unmountable boot volume

[nihalz]

hi

my parents have a macbook with leopard and xp pro installed via bootcamp...
today i get a message from them that they were unable to boot into xp and they get a BSOD saying

"unmountable boot volume"

what will they have to do to fix this error?

any advice?
thanks in advance

[nihalz]

oh and just found out, they cannot access osx either!!

what to do???

HELP!!!