I'm new to linux and I installed knoppix in my computer. My PC is a Celeron 1.7, 256 ram, VIA chipset, running Knoppix kernel 2.4 and WinXP Pro SP2. It's the client of a PC Duron 900, 256ram, VIA chipset, running WinXP Pro SP2. When I first tried knoppix on the celeron computer (from CD) I could surf internet and my home network. They were just 2-3 meters distanced. 3 months later i forgot linux and worked with windows. When I moved the linux pc to my bedroom i had troubles surfing the network at 100Mbps and "auto-negotion", even with WinXP. So I changed the value to 10Mbps. It finally worked. but when I ran linux again i didnt have the same luck. I read linux sets the net adapter to "Auto-negotiation" by default. I thought this was the problem and that I would needa set this value to 10Mbps.
How can I do it?

Assuming you are using the "via-velocity" driver:

the module parmeter "speed_duplex" is your friend
speed 100M bps half duplex
speed 100M bps
speed 10M bps full duplex
speed 100M bps full duplex
speed 10M bps
speed 1000M bps
speed 10M bps half duplex

sorry, as i told you i'm new to linux. where can i find the driver directory so i can edit the file?

Probably telling us the distribution you're using might help :-)

if you are using kernel 2.4 - check /etc/modules.conf