There are a couple things you can try.
1) Control Panel > Device Manager > Network Adapters > Right-click your wireless driver and access it's properties. Uncheck "allow Windows to turn off this device to save power"
2) In the same menu, check to see if you can update your driver. Look for an "update" button. Updating your wireless driver updates the software that it works with your computer.
3) Control Panel > Power Options > Advanced > Find your wireless driver. In the drop-down menu, set it's performance to "max".