Everytime my sister tries to connect to our internet via WIFI the internet crashes. The modem.router still says It's connected (it usually says disconnected when it stops working...go figure) and cant be rectified till the my sisters laptop is turned of and I reboot the modem. The router runs two computers so I know the WLAN connection is working...would it be my sisters wifi? Can you get a virus on such a thing?

Cheers!