re-establishing a network

OK, I admit it, I'm not a computer guy. I recently bought a new (Vista Home Premium) PC to replace my XP PC. On the XP PC I had a wireless network I could access with my PDA and laptop from almost anywhere in my house. With the Vista PC I fail constantly. I have read a handful of web articles on how to accomplish this but I apparently am missing a step.
The Netgear router is working on the Vista PC. Firewall on the laptop is (when I'm trying to get a connection) disabled. The Network status on the laptop and PDA show a good signal. How do I troubleshoot this?
FWIW, 'Connect to a Network' on the Vista PC and laptop show 2 networks - one secured and one unsecured. I don't know why. All I want is the secured.
Can I uninstall these wireless networks and create a new one?
The Vista PC also has a wired?/cabled? network to access the cable modem and NAS. Does this make a difference?