if neither helps, use 7zip or whatever unzipper you use to extract the contents of the exe to a folder on the hard disk. Now, open device manager, locate the display driver entry (or scan for hardware changes), right click it, choose update driver and browse to the folder where you extracted.
If none of this works, you'll just need to locate another driver that works.
Re-download the file and retry. Have you tried extracting the driver and updating it manually as I said in my earlier post? See, WDP is a buggy prebeta so not everything will work.