First, run windows update and make sure to have it look for optional updates to see of there are any for your card.  Search google for any known problems with the card.  Go into device manager and remove the device and let it find it and reinstall it.  If all that fails, go into the BIOS and disable the card.  Restart the computer.  Go into BIOS and re-enable the card.  If all these things fail try a USB WIFI adapter.

I've had several laptops where I've had to replace the wifi adapter for the exact reason you are saying but that was 7-8 years ago and I don't remember the details.  Not hard or expensive to do.