Laptop cannot connect to netgear router

I have recently been experiencing this problem for about 2-4 days now. For the past days I have been trying to connect my laptop to the router and I get the message that it cannot connect to it. I have a HP laptop using window vista home premium and a netgear router model WGT624 v3. I have experienced no problem with the router for about 1 year now. I have connected my laptop to other wireless networks and it works however mine doesn't. I also tried to connect my ipod touch to the router and it doesn't connect. It wasn't my internet connection either because I connected the laptop through a cable to my modem and there is internet connection. Strangely, my laptop detects the network but when I click on it same problem. No connection. It is such a pain so please help me out.

PS. Sometimes it does connect but only for about a few hours approx. 1-3. I have updated my laptop already(I think it was before the problem started? I am not so sure)