Help in connecting notebook wireless to wirelessmodem router

My housemate need your help in setting up his notebook to the wireless modem router using inbuild wifi Sony Viao notebook.

I tried to set it up but still unsuccessfull.

1. First of all, can I delete all the hardware connection device from device manager and restart pc, hoping it will reinstall all the hardware automatically and start from scracth?
because he got lan, 1394 (i don't know what is this, firewire?), netgear wifi.

2. Last time, I can see the modem router HOME from the notebook, provide the WPA shared key and connecting but cannot browse the internet, how to solve this?

3. I tried using tha lan cable and connect to the lan on the router to his notebook but no hope.
Normally, my wireless modem router can detect all the connection of the mac address from my router to any lan or wifi connection but I cannot locate his notebook mac address using both lan and wifi.

If I connect my pc 2 to the pc 1 via lan cable, it will detect the mac address automatically when searching, I add the mac address to the router and then connected and be able to use internet as well.
I also tried using PDA and my router can detect the mac address directly.

Could you please help me/my housemate to setup his notebook so he can use the internet using both LAN and WIFI?

I search google but it doesn't mentioned the wireless configuration to the router or maybe I miss it.
If you have the link, please let me know.

Thank you for your help.

Note: both wireless modem router and notebook has 802.11 b + g.

Hi...I've got another problem.

Now my PC 2 cannot connect to my PC1 or internet.
I already set obtain IP and DNS automatically but I've got limited internet connection.

only I change the ip and gateway then I can connect to PC 1 but NOT browsing internet.

Can you or someone please help me?

Thanks.