Network Traffic

Network: Peer to Peer
OS: Windows 2000
Router: Linksys BEFW11S4 10/100
NIC: Realtek RTL8139 10/100

In this setup ideally the network transfer rate should be 100MBits per second. However, The computers are transferring to each other at no more than 3.5Mbits per second.
I have tried the following:
1. Disconnected all computers except two computers to transfer.
2. Tried a different Ethernet card.
3. Tried using a HUB with Windows 2000 Adv Server as DHCP Server.

A solution to get this network up to par configuration would be greatly appreciated.
Par = At least in the 50 to 60MBit level.

Thank you