update bios

hi i have an award ( it says)asus acpi ? think it said aspi and 1007 v.10a revision its hard to see the log in screen goes by so quick its hard to catch so i went into bios it said asus p5a in there with some of the other stuff, nothing that much just asus p5a bios. its on an anthlon 111/450 motherboard with winddows 98 now (i need xp real bad )but anyway for now thats what i have how can i get the updated bios there are so many i cant find the exact one from asus can someone help me please i can go th drivers.com but i dont know which is the right bios there are so many little changes in them and i dont know if the prosesor has anything to do with the bios upgrade. can someone let me know what the bios i need is called exactly ( to some of you its so easy not me abviously) please im in need of help confused. and i dont want to mess it up the system isnt very compatable with 98 i did all my downloads, also i just put a new hard drive in im afraid ill mess it up i took me 2 days to figure out the pins so i could get my whole 80 gigs it only wanted me to get 33 i was told the bios does that since its old and only allows 33 so i had to install with the hd software. so i dont want to go through that again when i upgrade it sorry for babblling joni