My Panasonic Toughbook (model CF-18) connects to any wi-fi with no problem until I download anything (file,video,music etc.) then suddenly loses the connection.It immediately comes back when the download fails,then dissappears again on retry.Same thing happens when watching streaming video. Using windows xp and a Intel Pro wireless LAN 2100 3B mini PCI adaptor. 
I'd start by upgrading the wireless drivers on the machine to the latest available at Panasonic.
I'd also make some adjustments to the router.
Some things you can try here.
Many times these measures will resolve a lot of intermittent issues.
I'd also make some adjustments to the router.
Some things you can try here.
- For wireless connections, change the channel on the router, I like channels 1, 6, and 11 in the US.
- For wireless connections, try moving either the wireless router/AP or the wireless computer. Even a couple of feet will sometimes make a big difference.
- Update the firmware to the latest version available on the manufacturer's site.
- Reset the router to factory defaults and reconfigure.
Many times these measures will resolve a lot of intermittent issues.
