I have a new dell 1545. I was able to connect to the internet for the first few days. I have bought a linksys usb that has given me an extra bar for signal. I have installed a netgear router which has given me full signal but my computer says no internet access. When I click the bars it shows me connected but no interness access. I have never had to type in a password. There is a yellow triangle with an exclamation mark inside. I have disabled my firewall and still have this problem. I have caught wireless internet in my apartment before. Why am I having this problem now?