Here are a few things to try :
First unplug the power cord from the router let it sit a few seconds and then plug it back in. I have had to do this with some routers I have owned to get them "unstuck" from whatever funk they were in.
Second. Check to insure the encryption you are using on the router and your laptop is compatible. Sometimes an older encryption is specified on one device and a newer one on the other.
Third. Make sure you don't have differing wireless speeds locked in on both devices. For instance, your laptop might be locked in to using "b" speed while your router is locked in to using only "g" speed. If this is the case then they won't be able to communication with each other.
Fourth. You might have a bad wireless card in your laptop but I doubt this is the problem.
Hope these suggestions help.