More like 90% success and 10% fail;
Asus make good recovery software and the Microsoft disclaimer is aimed at the cheaper systems but there are always things that can go wrong.
1. I have personally used the factory reset to roll back to 8 on my Asus sonicmaster laptop when I first tried the 8.1 update and that worked fine--- took over an hour but worked.
2. IME Formatting your hdd to remove a recovery partition or adding a partition for say Linux WILL break the Asus recovery ability but that’s not something the average user does and you didn't mention it so I'm going to be brave and assume that didn't happen.
3. Disconnect the internet at the router (
not just flight mode) or Microsoft will be ever so helpful and try to download updates in the middle of your reset… they do try hard so we got to love them.
4. Disconnect the antivirus (
if you use Nortains then please un-install it)… in fact some people think the best idea is to do it from the bios
but I still like doing it from inside the system
*.
5. The Asus support page shows the steps for windows 8 only
http://www.asus.com/support/FAQ/1006133/ which isn't very helpful but the steps for 8.1 are almost the same…
Don't do a refresh--- your document files are now in a different format to what 8 wants so I only recommend a reset.
* I recommend doing it inside the system instead of the bios simply because you can see strait away if the system has a problem finding the recovery drive however that does also make anti-virus programs an extra step and I found a somewhat helpful youtube video that shows the bios steps for an Asus with some errors. If you watch the video you will see he waits too long the first time (
i.e. if the Asus logo comes up you missed it) and you can see he does get it the second time i.e. the please wait message is the system saying it detected the [F9 key] but he also holds the key down continuously which is wrong… press it repeatedly during the black screens until the please wait message appears.
Side topic;
Acronis backup software is so worth the money, get another hdd the same size (
or larger) and make an exact image of the system--- this will have the same key and will boot up without issues in the event of some future problem with your main hdd. It is a load off your mind just knowing that you have the backup hdd sitting in a cupboard somewhere.
p.s. Sorry for the long post but I figgure more info is better than not, with this topic and if it should fail the next step is to get your hands on a windows 8 iso and we'll walk you through it.