A friend of mine recently installed a DSL-modem and a NIC. However, he is able to receive data fine, but cannot send more than a few bytes. The problem occurs in all e-mail clients, ftp-programs, et cetera. He can send small e-mail messages, but no attachment or even a lot of text.

We've already swapped out the NIC, no improvement.

Home-built, 900 MHz
128 MB Ram
Win 98 SE