I found a post some where on the net. check to see if it applies to you particular shutdown.
This issue can be caused by a conflict with the onboard audio controller on your Nvidia or AMD gpu card and your motherboard audio.
You can try the following uninstall method which will fully disable the audio and should help eliminate the issues you are experiencing.
1. Go into Device Manager- In the Display adapers area right click on the 400/500 series card, and select "Properties" this will give you a listing such as "PCI Bus 3, device 0, function 0" If using multiple cards please check and note each listing.
2. Go under "System Devices", you will see HD audio devices. Check them to see which one matches your GTX 400 series PCI Bus location. Disable (not uninstall) the one that matches your 400/500 series card.
3. Check under "Sound Devices" and it should no longer be there (this step might or might not require a restart)