Via Windows XP:
Download and install archhttp:
Here is the archhttp utility
ftp://ftp.areca.com.tw/RaidCards/AP_Drivers/Windows/.
Head over to areca support and download the latest firmware file for you're specific card.
After installing archttp, find it in the programs and run it.
You'll see the top controller listed and under that is config.
Click on Controller and click "Launch"
You'll be asked for the login info:
Default: admin
passowrd: 0000
On the left sidebar, click ont he last item, then navigate to upgrade firmware or the equivilant.
Now browse for that firware download you got from Areca for your specific card. You should have 4 files, bios, boot, and firmware. Update them one at a time and wait for the progress bar to finish and a status message to appear. You can do all four consecutively and then restart the system.
The new firmware will update after reboot.
Apologies for not having screenies, I was in a rush to see if it worked