Internet is going VERY slow!!!

Today i formated my computer and now my internet is going very, very slow. I have always had two different internet connections, one is the NVIDIA nForce MCP Networking Adapter and the other was the 1394 Net Adapter. Before i formated i was using the 1394 net adapter, but now it will only use the NVIDIA nForce MCP Networking Adapter, which is a lot slower. The NVIDIA nForce MCP Networking Adapter is only at 100 mbps and the 1394 Net Adapter is at 400 mbps. Like i said, before i formated i was using the 1394 net adpater and it was super fast, but now i can only use the NVIDIA nForce MCP Networking Adapter. The NVIDIA nForce MCP Networking Adapter send and recieves packets but the Net Adapter doesnt. Both of them are enabled but the Net Adapter doenst seem to be working. Im running out of ideas on how to fix it, so im asking anyone who has any ideas on how to fix it, to please send any suggestions

The 1394 net adapter is firewire, it doesn't really have anything to do with the internet. I don't know why you think you were using that connection before, the MCP networking adapter is the one that is for the internet, and the one that will work.
Post your system specs, and what your internet connection is, so we can try to find the problem.