OK, need a PC genuis here, bearing in mind I'm fecking useless with PC's

Bought a wireless router yestetrday so my place is now 'wi-fi'. Laptop is wireless, router working perfecly but laptop not picking up wi-fi signal from my base PC. Apparently there's a wi-fi switch on my laptop but I'll be fucked if I can find it.

Any ideas ? Plain English please, I'm a PC idiot