wireless network problems

Hi

Im having problems linking the three PCs in my house together to enable file/printer sharing etc. Connecting to the internet is not a problem and i could connect to my bros PC before i had to reset everything again (because i sort of broke it!)Mine and My bros PCs are wirelessly connected and the downstairs one is connected to the router by a cable.

If anyone could help me i would be very greatfull.

Thanks

What exactly is the problem you're facing?

Well,

in the bottom right hand corner it says LAN , a network cable is unpluged. Theres another symbol that says 'wireless network connection (NETGEAR1)' is connected.

When I go on 'my network places'I can see my shared documents and my brothers shared documents but nothing from downstairs. When i click on 'view workgroup computers' the only one I can see is mine.

Also my dad wants our network to be encrypted.

Hope this makes it a bit cleare
Thanks