- A change to your laptop's software or configuration. Did you install a new patch or service pack that might have impacted your laptop's network connection configuration? Try removing and re-adding your wireless connection (using the Control Panel), removing and re-installing your wireless card (using the Device Manager), or using System Restore to "roll back" to a date that you know your card was working. Review XP's Event Log to see if you can spot when the problem started and what else happened on that date.
- A change to the router's firmware or configuration. Did you upgrade the router's firmware, add another MAC address to your router's ACL, or reboot the router around the time you started having trouble? Given that other stations are working fine, a problem on your router is less likely, but perhaps the ACL entry for your station got corrupted. Try removing and re-adding that MAC entry, or temporarily disabling the ACL. Review the router's log when you connect to see error messages that might help you diagnose the problem.
- A change in your wireless network. Environmental conditions that influence signal strength and coverage change continuously, so a new source of interference should always be considered. If have trouble connecting just from one spot, try connecting from other locations, closer to the router -- I assume you have already done this. If the problem occurs no matter where your laptop is located, is another station using your card's MAC address or your station's computer name/IP address? Is your router or another station in your office using "g-only" mode, and thus interfering with your older 802.11b card? Check your router's log.
- A broken wireless card. I usually rule this out by installing a flakey card on another laptop. If I have the same problem on more than one laptop, then I have reason to suspect that the problem is with the card (or its firmware), not the original laptop. Hardware failure isn't as likely as software/config error, but consider it anyway. If you suspect the card, try updating the card's firmware. But wireless cards are so inexpensive now that buying a newer 802.11g (or in your case, pre-n) card might be worthwhile.
Note: I have not suggested checking WEP keys or WPA PSK values because you indicated that these options are disabled in your router. But the symptom you describe occurs VERY OFTEN when the router and station have a WEP key or PSK mismatch, so other readers should check this first before considering other possibilities.
This was first published in September 2005