Afew things may be going on.
If a static ip is involved perhaps another device has grabbed that ip causing a conflict?
In some rare cases this can happen with a Dynamic ip but not likly.
You may need some updated Wireless card drivers
, or could try disabling the wireless card, restarting your laptop, and then once it is booted up, you can enable it. This worked for my issue I was having with my desktop pc on wireless.