Failure reverting changes loop - boot to safe mode

Hello,
I know this is a quite common problem, but it's causing me no end of issues.
Windows fails to install updates and has to revert. It gets itself into a perpetual loop so I can't get into my system at all.

I Have heard two main solutions:

1) Initiate refresh/repair by shutting down, powering up, and holding shift whilst spamming F8 or F9. Neither work for me.
2) The other option I have heard is to boot into safe mode from the BIOS. Except with windows 8, I can't find in the bios an option to boot into safe mode.
On my old acer, advanced boot options were hidden from the landing screen and had to be enabled by pressing F2 to get into set up. You then enabled a setting, and the next time you restarted, you pushed F10 and had new boot options.

My laptop is a Clevo with Windows 8 and I can't find a way to boot safely or get into my laptop at all.

Can anybody help?
I will appreciate it so much!

Henry

After a re-install a few months ago, I had this happen when windows tried to install ~80 updates at the same time. I just re-installed again, and updated before installing most of my software, 2nd time it managed to update ok.

Hopefully someone has a better solution for you, since you might have stuff not backed up that you need to get to.