4. How to resolve installation failure of the X3's DAC driver on Windows 8/8.1 64bit?

A: Known issue:  the driver will fail to install on Windows 8 64bit computers.  This is related to the driver signature module.  The driver has not been signed for Windows 8 64bit and will not work while driver signature enforcement is in effect.  
Please disable driver signature enforcement as follows:
Mouse over upper right corner of screen->settings->Change PC settings->General-> Adancedstart-up >Restart now->Troubleshoot->Adanced options->Start-up Settings->Restart->Press F7 to disable driver signature enforcement.
After such a restart, the computer will be able to install unsigned drivers, but give a warning when this happens
(as is the case with installation in XP, Vista, Windows 7), just click Install anway to proceed.
   
Note: Please refer to the attachment for a walkthrough of the process: Click here .