Sony PCG-SRX99 VAIO User Guide (primary manual) User Manual page 175

I cannot access the Internet.

Make sure the Wireless LAN switch on the computer is in the ON position or the Wireless LAN PC Card is properly
inserted.

Check the access point settings. Refer to the instructions supplied with the access point.

Check if your computer and the access point are connected to one another.
 Move your computer away from obstructions or closer to any access point you may be using.
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