Optimizing NIC performance

Anyone know how to tweak the system to utilize 100% or at least 90% of the NICs banwidth? I have a dual xeon 2.4 GHZ processor with intel gigabit nic running windows 2000 server and a 3com 3c90x on a P4 2.0GHZ running windows XP. They both wired to a linksys wireless G Cable/DSL router. It took about a day & half to transfer about 35GB of data. More like 17 hours. I’ve try the tweaks from speedguide.net but no help. Any help will be greatly appreciated.