48-bit LBA Support - HDs Over 137GB - Advice?

Hi I'm planning to upgrade to a 160GB HD however, I have read some info
about recognition issues with MBs and XP. It appears that older MBs pre Jan
1st 2003 do not have support for 48-bit LBA. XP will only read 137GB, no
more.

To be honest I cant remember when I bought mine but according to a list of
Bios support for my MB (Asus A7N8X Deluxe) the Bios needed for the 48-bit
LBA Support is 1001.C. Sandra Pro 2003 stated my Bios as:

Asus A7N8X2.0 Deluxe ACPI Rev 1002 Beta 012
Plug and Play version 1.00
SMbios/DMI Version 2.20

So am I in need of an update? To be honest, I would rather avoid updating
the bios as I have never updated them and cant afford to replace the MB
right now if it all goes pear shaped.

Alternatively, I have been reading the Microsoft knowledge base about SP-1
and changing the registry which I would prefer as I can always re-install
Xp if it goes wrong. Would the reg fix work without a bios update?

I understand that I cant have just the one partition on the HD as I wont be
able to have a partition larger than 137GB but I partition my HDs any way
so that will suit me well.

Any advice would be most appreciated.