Downloading this driver worked (both WiFi and WiDi now work correctly):
http://www.samsung.com/us/support/owners/product/NP900X4C-A01US
Scroll down to Wireless LAN 15.0.0.75 (Win7 64bit), click ZIP, download the ZIP file.
Extract the file
Select the driver INF file from within device manager (update driver)
Run setup.
-Alex