Sony PCG-NVR23 Notebook Realtek RTL8139 Ethernet Controller Driver 5.504 Windows XP.. Do use the latest driver version available, it will help you use the facilities of your hardware easier and better. An old version can create hardware conflicts and errors in function. Try to stay updated with your drivers monthly or sometimes weekly. Chose wisely the specific drivers: motherboards driver, bios, graphic cards drivers, modem drivers and so on. Chose the right driver for your hardware and try to make backups of your system every time you want to make a change.