Sony PCG-GRX500 VAIO User Manual page 177

I cannot access the Internet.
 Make sure the Wireless LAN PC card is properly inserted into the PC card slot on the left of the notebook.
 Check if your notebook and the access point are connected to one another.
 Check the access point settings. Refer to the instructions supplied with the access point.
 Move your notebook away from obstructions or closer to any access point you may be using.
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