Hp compaq mother M2N68-LA - Compaq NARRA3-GL8E HP NARRA3-GL8E Desktop Motherboard 462798-001, M2N68-LA

there is none
HP told you that,! but did you post first? i bet not to them.
why not take there word for that.
or ask on there forum , fixya is not hp.com

ask them only they can go into old HP FTP servers and find it. (if not deleted as most are this old)
there is no public index to that, they deleted the index as you so clearly witnessed.

Learn that you did not post your full service tag
guess what, the BIOS must match that perfecty
or you will BRINK your PC, liked 1000s do at hp.com
all the time. endless mindless brinking of PCs.
due to that one fact.
not getting HP to match it PERFECTLY.
the even have patches for w8 and 10 , too.
on some PC but not any for 10 year and older PCs.
why not just upgrade this old PC (retire it)

HP 5189 1661 M2N68 LA Narra3 GL8E Desktop Motherboard AM2 SATA MicroATX

http://www.asus.com/Motherboards/M2N68/#support

find this.

http://support.asus.com/Download.aspx?SLanguage=en&m=M2N68&os=30

There has been a lot of confusion going on around the net. However I find the driver which should work just fine with your model. However the driver is from HP/COMPAQ and the model is M2N68-LA (Ivy8)

You can download the drivers from this link
Documentations will be available here

If you have doubts let me know.

Yes, it has an IDE connector. BTW it's not an men69-la, it's an Asus M2N68-LA
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01357135&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=3740351

if you really dont have a mother board driver.. i suggest to convert in WINDOW 7 O,S coz win7 doesnt require mobo drivers and chipset
its automatically read the existing chipset..

below link might be helpful
http://pc-and-peripheral.blogspot.com/2009/10/asus-m2n68-motherboard-for-hp-a6455.html

A BIOS checksum error can be caused by a nearly flat BIOS battery.
I would replace the BIOS battery first before attempting to upgrading the BIOS.
Some motherboard BIOS firmware is upgraded by running a program that has been copy to a DOS boot disk or the upgrage maybe done from within the BIOS setup. These firmware upgrage and instructions are on the motherboard WEB site, in your case the Compaq/HP WEB site. Make sure you select the upgrade for your model motherboard.
NOTE it is possible that if you make a mistake you could ruin your motherboard, if you are not sure seek help from a computer savy friend.
Use this link :-
http://h18000.www1.hp.com/cpq-country/cpq_support.html

http://www.bioticaindia.com/download.php?file=m2n68-la

you need to register first before you can download the file