Could not connect to wifi through wireless but could with LAN ethernet

I really need help, please

So, 3 days ago I was connected to my wifi through wireless just fine
But now, whenever I try to connect, it says "unable to connect"
The signal is fine, the password is right, it would try "connecting" but ends up "unable to connect"
Been working fine all along and suddenly this occur

So, I tried to plug in the LAN cable and through the ethernet, it could connect fine!!

I have no idea why this is! PLEASE HELP!!

My computer: WINDOWS XP (32 bit/Home Edition/Version 2002/Service Pack 3)
Wireless: Intel PROSet/Wireless 14.3.1