wireless network is reading the signal but its not connecting help?

[Zech]

so i have a netgear usb adapter and it is picking up the signal from my router but its not connecting. i click on it and then click connect. then it loads and finally gives me a message saying "windows is unable to connect to the selected network. the network may no longer be in range. please refresh and try again." so i do that and it reads the signal saying i have four out of five bars but it still wont connect. please help