Connected online but not shown on Network and Sharing Center or on taskbar

I have a Dell Inspiron 1520 running on Windows Vista 32, my router modem is a Motorola SURFboard SBG901. About a couple of months ago on this computer, I wasn't able to see that I was connected online either from the bottom right icon on my task bar (it just shows the two computer monitors with an "x" , which when you highlight over it tells you "Not Connected, You are currently not connected to any network.") Neither can i see it on my Network and Sharing Center, which states: "Not connected- Wireless connections are available." On the network map it only shows my computer and then the line which has an x on it. If you click on the x, or select diagnose and repair from the task bar, it informs me nothing is wrong with my computer. If i go to connect to a wireless network, it shows there that I am all ready connected to my network. I can open up any of my browsers and they all work fine, i can access the internet with mostly no problems. I wasn't bothered with it at the time, but since then I have moved to a new home and thus have a new internet service and all, with this motorola cable modem. my new wireless network is an unsecured network, which obviously I want to secure it. I can connect to this network but I can't access via Windows any of the properties to make it secure. I read the modem manual, which tells me to connect through an ethernet connection and access the configuration manager via the ip of my router on a browser (192.168.0.1), but that doesnt load either. I have other wireless devices (Ipod Touch, and PS3) I've had other people bring computers over, and they all detect the network, but none can connect to it. I have all ready gone to the device manager, uninstalled and reinstalled my network driver, i have also updated it and still nothing. I hace checked my ipconfig, and my ip addresses are set fine it seems. Thanks for any help.