I want to compile network driver. Which souce should I get?

I downloaded this knoppix:
ftp://ftp.kernel.org/pub/dist/knoppix/
KNOPPIX_V5.0.1CD-2006-06-01-EN.iso 712926 KB 6/2/2006 12:00:00 AM

Knoppix cannot detect on board ethernet on my computer so I need to compile the driver. Which sourcefile should I get?

The oldest version?
http://www.kernel.org/pub/linux/kernel/v2.6/
linux-2.6.17.tar.gz 18-Jun-2006 02:10 49M

Or the newest version?
http://www.kernel.org/pub/linux/kernel/v2.6/
linux-2.6.17.14.tar.gz 13-Oct-2006 20:04 49M

Or other version?