WiFi Troubleshooting Notes

June 28, 2005 by Fernando Duran

Here are some Wireless 802.11 troubleshooting notes, many are Windows specific.

Trying to sort by easiest and most likely to solve the lack of WiFi communication problem.

Most of the problems are solved by rebooting computer and router and making sure that the settings in both (encryption etc) are the same.

Questions: has wireless ever worked? is it working on and off? was something installed or changed before it stopped working?


  • Check lights in network card and router or Access Point (AP), check for activation from wireless switch or keyboard combination in some laptops

  • Power-cycle AP, reset network: log out of Windows

  • Check both computer and AP have same 802.11 version of WiFi

  • Dropping connection: check for distance, interference (portable phones...), use channel 11

  • Check for running firewall or virus in computer

  • Check if AP has WEP encryption key enabled. Disable momentarily for testing

  • If AP never worked: try connecting directly with regular Ethernet patch cable

  • Check for MAC filtering in AP

  • Check for updated driver in router

  • Check for duplicated network name; change the name in AP configuration if so

  • DNS problem only: ping known IP, like yahoo: 66.94.234.13

  • Windows: check with ipconfig if computer is getting DNS Suffix, IP address & gateway

  • Windows: delete other routers that show up in wireless list

  • Windows: check card in Network Devices, check if it has power saving feature

  • Windows: check that "Obtain DHCP automatically" is enabled

  • Windows: check that option "Use Windows to configure my wireless network settings" is enabled

  • Windows: check windows version; SP2 has other WiFi interface

  • Windows: check that the service "Wireless Zero Configuration" is running in Start -> Administrative Tools -> Services

  • Windows: disable network bridge connection

  • Windows: run tool: netsh diag gui for diagnostics

  • Windows: release & renew DHCP: ipconfig /renew

  • Windows: reinstall network stack by running: netsh int ip reset resetlog.txt

  • Windows: remove network card from Device Manager and reboot to be reinstalled automatically