Gigabyte GA-Z77X-UD5H Restarts with New Monitor

[SC]

I have a Gigabyte GA-Z77X-UD5H and Windows 8 64 bit. The PC has been shutting down fine with an old monitor connected via VGA to a R9 280X GPU. I've now installed a new Viewsonic VP2770 monitor via DVI. When I shut down, the PC nowrestarts instead. Is there a BIOS setting or Windows 8 setting to ensure the PC shuts down correctly?

[AndyM]

I believe this is a common problem with Windows 8 as when Shut Down it is only basically sleeping so it boots up quickly.  I have Windows 8.1 64 bit and it suffers from the same problem.  Last night, my computer (a desktop) had been Shut Down, but still switched on at the wall socket for over an hour when it restarted.  I noticed that on restart my Internet was down.  So I have now unticked on my Network Adapter, "Allow this device to wake the computer".  This can be found via:
Device manager
Network adapters
(the name of your Ethernet adapter)
Power management tab

I don't know if this has solved my problem but I shut it down this morning for over 2 hours and it didn't restart.