Can't connect via ethernet

Hello,
I had some problems with my desktop that led to me re-install windows. Since then, I can only connect to the internet via the USB cable. I am wanting to hookup my router so we can also get online on the ps3, but I'm not able to without connecting via ethernet. All of this same equipment worked on this same computer prior to the reinstallation of windows. Any suggestions?
THANKS!!

Hi,

Please go to Start > Run > type CMD in Run window and press Enter.
In Command Prompt, type next command and press Enter to run it :

sfc /scannow

Note : If your computer ask you for Windows XP cd, please insert it in your CD/DVD Drive and press OK.