Thank you Jon for providing me the very clear info.
I checked the link and found the following under my service tag. I think you are right, I am using the dell wireless.
CARD (CIRCUIT), WIRELESS, MINICARD, DW1490, BROADCOM CORPORATION
Actually, I also tried to install DW1490 driver on the d630 yesterday, but it won’t allow me to install it, said it is not for this system. I installed the dw1490 on the d620, which it works perfectly.
I'll call dell at the same time to verify this.
Your help is highly appreciated.