The latest BIOS update should be on ASUS' website.
There's a tab at the top called Download. Then a section called Download that says
"You may download product BIOS, Drivers , User Manual as well as Utilities here."
Then a column to the left that has a Download text box.
Type in: A8N-SLI and click the search info button.
Then click on the A8N-SLI link.
This provides a choice of 4 download sites for the BIOS. However, there are instructions to update the chipset drivers before flashing the BIOS.
It says:
A8N-SLI Bios version 1014
Please do read the description before updating BIOS
To avoid crashing file system, please do update the chipset driver to below version prior to this Bios.
For WinXP 32bit system, please download and update chipset drivers V6.65 or later
For WinXP 64bit system, please download and update chipset drivers V6.65 or later
For Win2k/2003 32bit system, please download and update chipset drivers V6.66 or later
For Win2003 64bit system, please download and update chipset drivers V6.66 or later
1- Support new CPUs. Please refer to our website at:
http://support.asus.com/cpusupport/cpusupport.aspx
2- Update awdflash.exe to v1.15
3- Remove 2.88MB floppy item value
If you scroll down the page, you will find links for downloading chipset drivers.
All the best