just torrent the CD
all you need is the software
grabbing that isn't an issue
it is only when you crack the key they get pi55ed

as for Vista, it won't work against an XP setup

and also to me too, the HDD is destined to fail soon
generally, I have found that once a system starts giving out error messages re - OS bit n bobs missing
that it will soon fail totally

can you not slave the drive ASAP
grab all the data from it and back it up

ideally BEFORE you tyr the rescue?

luck to you
and if you were local, I would send you a CD, got a pile of genuine MS XP Pro discs, from my various jobs over the years
never could just drop em into the bin

luck to you