trying to install and i get a fatal error...

hi i chose to do and upgrade and it copies all the vista files and then goes
onto the next section and restarts the pc. It restarts as windows xp but in
the c:/ there are vista folders. what should i do?
my pc is a hp one with a 200gb hdd which has been partitioned (5gb / 180gb)
by them for there recovery setup. Is it possible to do a full installation by
booting the pc with the vista dvd but be able to keep the current windows xp
os and the hp recovery partition? what i really want to do is be able to have
the ability to dual boot vista/os but still have the hp recovery partition.
(i think i need the recovery pasrtition because the pc did not come with any
cds, instead hp told me to make a recovery disk which when i boot up the pc
with it in gives me access to the hp partition to set the pc up to how it was
when i first bought it)
any ideas appreciated,

many thanks
Hish