Asus UX31 Won't Boot

Good afternoon all,

I upgraded my Asus Zenbook UX31 to Windows 8 just before Christmas. Everything was working fine until a couple of week ago when I did some other updates. Now it will power on to the point of turning on some lights, but it won't get up and running unless I have it plugged in (and then only sometimes). As a laptop which I'm pretty used to leaving on/sleep most of the time (which it had been excellent at) this is fairly annoying!

Naturally though, I'm pretty sure it's my fault:

I remember there being a warning message from the system or a driver installer or similar about "instant on" not working for some users once it was installed.

Stupidly I thought I'd be able to find this warning once again if something went wrong - no luck there! I've looked at the action centre message archive, and there's nothing about it there. I'm not sure where else to look.

So, my questions:

Where is a comprehensive list of errors, warning and recent installations on my Windows 8 computer? I think I will be able to fix the problem by working backwards.

Does anyone know a way to combat this problem from their own experience?

Thanks to all in advance.