Ethernet controller driver not to be found !!

Hi,

I installed Windows XP Pro on my Inspiron5150 and I have not been able to figure out how to make it work on cable Internet connection using the RJ45 connector. Since in the hardware devices wizard it says that the Ethernet controller in not installed properly. I tried to look for it in the Drivers Installation disk provided with the system with no luck. It is also not found in c:\windows\system32\drivers directory. So please advice me how to make it work ? where to find the driver appropriate for my system ?

Thanx!