So I got a wireless router so I could connect both computers the our broadband connection. The router is situated beside one computer, so that picks it up no problem.

But my other computer, in the garage, can't connect to it. The wireless device can find it when I search for connections, but it can't connect! I can even connect to other connections I find in my area that it picks up, but it can't connect to MY wireless router!

There are 2 concrete block walls between the router and my computer in the garage, could that make a difference? It does detect it, just can't connect! (Mind you, it does say it only a week signal).

Any idea?

Cheers

Yes, there is a 99% chance that those concrete walls are interfering with your network. Radio signals as weak as wireless network signals don't pass through concrete well.