heres the solution to my problem.Thanks ....It is Win 8 Driver Signature Enforcement issue. Press (WinKey)+I....Chose PC Settings - Advanced startup - Restart now. On the blue screen select Troubleshoot, Advanced options, Startup Settings. Click Restart button. On reboot the blue screen with Startup settings appears. Choose option 7 - "Disable driver signature enforcement". After reboot just repeat the driver installation process. Windows Security dialog pops up with a "Windows can't verify publisher of this driver software". Choose Install the driver software anyway.