Sony VGN-A600P - Manual (Page 209)

Networking
Why can't my computer connect to a wireless LAN access point?
 Connection availability is affected by distance and obstructions. You may need to move your computer away from
obstructions or closer to any access point you may be using.
 Make sure the Wireless LAN switch on the computer is on.
 Make sure power to the access point is on.
 Make sure the access point is displayed in the Available networks window.
 Make sure the encryption key is correct.
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