fyi.
I don't have the BestBuy model, but below is a screenshot from my G46VW-BHI5N43 which had the Widi software already installed.
1. Have you made any upgrades to the wireless card? You will need to use the Intel approved wireless card for WiDi.
2. If you don't mind erasing everything and reinstalling the factory image, try this and make sure your device manager looks clean.