XP will not pick up drivers...
Vimal was incorrect that XP will pick up your drivers because it won't... and I doubt there is an IRQ problem.
Here's how you'll fix it. Go into device manager again and right click on the network adapter.
Uninstall it.
Reboot the machine with the card still plugged in.
Once the machine reboots, XP will automatically pick up the device and install a RealTek Driver to it (assuming you already haven't copied or installed the driver to system before).
Go back into device manager once your computer is back up and right click on your network adapter and click the first option which is update driver.
Make sure the software CD is in your CD ROM of course and a wizard will pop up.
select the "Install from a list or specific location (Advanced)" option and hit next.
Next select the "Search for the best driver in these locations" option and put a check in the box that states "include this location in the search. Hit the browse button in the middle of the dialog box.
Select your CD rom drive and select the WinXP directory. So now if your CDROM drive was your D drive, the path would be D:\winxp. Then hit next in the wizard.
Your Network card will come up in the box. Highlight it and click next again.
It might mess around copying the files for a minute, but when that's done, click finish. And there you go
On WIN XP you shouldn't have to restart, and if you choose not to, check the installation by going back into device manager and network adapter. The adapter should now be renamed to the correct card.
That should do it. And if you don't have the CD, go online and download the drivers on another computer and burn them to disk at your house or a buddy's with a cd burner.
If you ever have any other issues and want real quick answers, go to my new BB listed in my signature.