It might be the fault in the card itself. Get hold of another network card and test that.
I had many network cards that were faulty because of this, answer, i just returned them and had another replacement. In the end you will get connected. But i will do my best on your issue on here.
Go to your network card settings and change the "10t half duplex" to Full. You might have to change it a few times until it works though.
I have mine on "100Base-TX (Full-duplex) " if that helps at all, that is if your card can go up that far.
Also:
Edit the connection settings for the broadband connection to enable automatic detection:
1). Start Internet Explorer.
2). Click the Tools menu, and then click Internet Options.
3). Click the Connections tab.
4). Under Dial-up and VPN Settings, click the broadband connection, click Settings, and then click Automatically detect settings. then Click OK.
More info if needed:
How to Configure Windows XP for PPPoE
To create a broadband connection using PPPoE, use the following procedure:
1). Click Start, click Control Panel, click Network and Internet Connections, and then click Network Connections.
2). Under Network Tasks, click Create a new connection, and then click Next.
3). Click Connect to the Internet, and then click Next.
4). Click Setup my connection manually, and then click Next.
5). Click Connect using a broadband connection that requires a user name and password.
6). In the Connection Name dialog box, type the name of the ISP. This becomes the name of the connection. Click Next.
In the Internet Account Information dialog box, type the user name and password. Additional checkboxes allow you to specify whether this connection and its user name and password is available to all users (selected by default), whether this connection is your default Internet connection (selected by default), and whether to enable the Internet Connection Firewall on the connection (enabled by default). Make the appropriate selections, and then click Next.
In the Completing the Connection Wizard dialog box, review the settings. If you need to modify any of them, click Back as many times as necessary. If all the settings are correct, click Finish.
In the Connect dialog box, click Connect to attempt the connection.
http://technet.microsoft.com/en-us/library/bb456997.aspx
More info that might help you:
How to configure Internet Connection Sharing in Windows XP
http://support.microsoft.com/kb/306126
Even though it says "Internet connection sharing" it still has some idea's on how to connect to the internet for you.
By the way, have you got Windows XP SP3 installed?
If not then go here:
http://www.microsoft.com/download/en/details.aspx?id=24
Or you are still having trouble, go here and download this little gem, it just might help you:
Welcome to the Fix it Solution Center
http://fix-it-center.en.softonic.com/
