Turn off laptop, remove main battery and disconnect laptop from domestic power. Now hold the Power Off/On button for about 30 seconds, which discharges the motherboard. Re-assemble, power on and cross your fingers. At least it is easy to try.
It seems that you are unable to boot the computer into the desktop as you are stuck on the Aptio Setup Utility page. I guess, you might have made some changes in the BIOS of the computer and due to which you are unable to boot the computer into the desktop and it reverts back to the BIOS Setup page, every time you restart the computer.
This seems to be issues with the BIOS Setup Utility. So, I would suggest you to get in touch with the ASUS Technical Support to check what exactly the issue is.
In Windows 8, Microsoft has introduced a new boot loader that decreases the boot time of the computer. Unfortunately, in order to do this, Microsoft had to remove the ability to access the “Advanced Boot Options” screen by using the “F8” key as soon as the computer starts. Thus, you will not be able to access the safe Mode using “F8” key on Windows 8 computer. This is available only on the previous Windows Operating System.
In Windows 8, when your computer is in a “No Boot” situation, and if you want to try booting in “Safe Mode”, then the only option is to boot the computer from a Windows 8 installation disc and to access the “Advanced Startup Settings”. If you have Windows 8 installation disc, then you may try the following steps to get into the Safe Mode.
a) Insert the Windows 8 installation disc in the DVD drive and boot the computer into the DVD.
b) In the “Windows Setup” dialog box that appears, set the Time and currency format, Keyboard or input method and the language to install and then click “Next”.
c) Click on “Repair your computer” from the lower left corner.
d) From the “Choose an option screen”, click on “Troubleshoot”.
e) Click on “Startup Settings”.
f) Click on “Restart”
g) On the Startup Settings screen, choose “Safe Mode”.