Have you actually installed the driver? It's a fairly common error for people to think that they simply need to download the file (and then, possibly, to reboot their computer). The file which you download isn't actually the driver, it's just the set-up program for the driver. You need to double-click on it, to run the program which then installs the driver.
(If you've already done that, I apologise for wasting your time but I thought it best to get a known 'user error' dealt with first).
Chris