SYMPTOM: Laptop connects fine via wired connection but using wireless, it seems to be able to connect to router (at least as indicated by system tray icon) but can’t access Internet or other computers on the LAN.
SOLUTION: Need to re-install wireless driver. Download the file 77wc39ww.exe. Double click on that file and follow prompts. Allow the wizard to over-write all files. Re-boot computer.
NOTE: Might be necessary to turn off wireless security (using the router interface on another computer) and then turn it back on.
EisenGuide 