Trying to set up my iphone but it can't find Wi-Fi network?

I recently got my iphone fixed and it was restored to factory settings, i'm now setting it all up but when i come to chose a Wi-Fi network i put in all teh details if my Wi-Fi network and it just says Wi-Fi network can't be found. Its not my Wi-Fi because i tried connecting it at my friends house as well and it said the same, i can't skip past this bit it want be to put in a Wi-Fi network what should i do?

i think its running ios 7 btw

Your phone has to scan to recognize the network and only then can you input the information and get an ip from the router. If you can't scan for networks, something is wrong with the wireless chip inside your phone or your phone is on airplane mode with Wi-Fi off.