BIOS RTC alarm wakeup fail if Windows 8 enabled "fast startup"

Question

Hi guys, I love the Windows 8 new start screen but seems that the new "fast startup" feature break some functionality of my motherboard. It's Asus P8H67-M Pro, running a UEFI BIOS.

I set my computer to wake up at 08:30 in the morning everyday using the RTC alarm wakeup feature in BIOS, this works well when I'm using Windows 7, but now with Windows 8, my computer won't wakeup in the morning anymore.

Then I have some troubleshooting with it, thinking about the differences between Windows 8 and 7, one of the big different is the "Fast Startup". So I tried to disable it in the Power Option, and then, the RTC alarm wakeup works again!

Now I'm confused, why Windows 8 can affect the BIOS behavior like this? the "Fast Startup" should be an OS level thing, and after I shutdown the computer, it should be in the same S5 power state right? What components are affected by the "Fast Startup"? And most importantly, how could I enable "Fast Startup" with RTC alarm wakeup working?

Thank you very much for your time on reading this. Hope I could get some feedback from you soon.

Best regards,

Steve

Answer 1

Fast Startup places the system into Hybrid" S4, not S5.

Try making a windows scheduled task to wake the system up instead.

Answer 2

I too have this problem and would like to know the answer

Regards,

Steve