Wireless network down - how to fix??

[Monsieur]

Working perfectly until 30 minutes ago - daughter and friend wanted to use friend's laptop via my wireless network. She asked me for the router's PIN which I duly gave after reading it from the router's sticker on back of router.
Since then I've lost all wireless connectivity in the house.
I'm with virgin media, on their top-notch broadband and am using a D-LINK DIR-615 router.

Anyone any ideas on how to fix this

 

[Schtum]

Have you re-booted the router? Are you sure you didn't give her the router's serial no. when in fact what she needed was the WEP or WPA encryption key?

 

[(RIP) Bin Ridin]

Did you accidentally switch it off when you looked up the wep?

 

[Monsieur]

Now working
Rebooted the router twice, did something on the computer (don't know what) and bollocked daughter and friend