My wife's computer is having a strange issue. She started having wifi connection issues, so I tried everything I could think of: disconnecting and reconnecting, turning the wireless card on and off, rebooting, ipconfig /renew, reinstalling K9, uninstalling K9. Nothing was working, but all other devices on the network worked fine.
ipconfig shows an IP address. Pinging Google usually times out, but sometimes gets a response. Windows shows a wifi connected icon in the system tray.
The strange thing is, sometimes it would just work perfectly.
Eventually, I narrowed it down, and it seems that when the laptop is plugged in it works fine, and the issues only occur when it's running off the battery.
The laptop is a Dell Vostro 3750, around 3-4 years old. The battery capacity seems pretty good, it can last several hours on a single charge. Is it possible that the capacity didn't degrade, but the ability to output the required voltage did, and as a result there isn't enough voltage being generated to fully power the wireless card?