In Windows 8 it is impossible to start safe mode by pressing the F8 or F2 keys during system startup. Those who have already tried Windows 8 will find it impossible to activate the F8 key during PC startup. The reason for this is the speed with which Windows 8 starts, leaving the Windows boot loader a short time to detect safe mode execution using the F8 key (approximately 200 milliseconds). In addition, the entire boot sequence has been modified in Windows 8.
Note: In case of a problem that prevents Windows from starting normally, Microsoft guarantees that the user will automatically switch to the Start options menu.
How to Boot Windows 8 in Safe Mode
On a system that works properly, to access the startup options you have to go through the sidebar (Windows + I key) and select Settings > Change PC Settings > General Use > Advanced Start (Restart Now) . You will see the Choose an option with several options page, select the option Troubleshoot :
Select Advanced Options :
Select Startup Settings :
Press the Enter key , then press the number key for safe mode:
Or select another key corresponding to another one of the modes or functions (you only have to press F1-F9 depending on the number in the safe mode):
The system restarts and displays the Desktop in safe mode.
Note: Repeat this operation each time you need to start in safe mode.