Network controller for my sony vaio ntbook

Hello,
am jay.i changed my laptop O.S from windows xp to windows 7,since then i lost my network controller.cos wen i go to my device manager,it shows me a question sign b4 d network controller.these are the details i can gather about my laptop.
sony vaio notebook
CPU:Intel N270-1.6G
10.2 WXGA 1024*600
HDD:160GB SATA
WiFi 802.11 a/b/g
windows xp-windows 7 viena
service pack 3
version 2008-2009
wish and hope for a positive result
TNX....