Full System Recovery :
it formats/deletes all data + all partitions (even recovery partition)....& then re-installs Windows .
to run full system recovery, insert the Recovery Disk in CD/DVD tray & restart the system, then on just follow the onscreen instruction to run it.
just make sure the recovery disks are error free (CRC error & you're done

)
when Vista gets installed, all the required drivers & s/w (Anti virus, HP s/w...) also get installed.
or better call HP Customer Support, they'll guide you.