Thanks hmscott for ur reply : comprehensive and precise as always.
in fact by reading ur post I just realized that i got the latest Bios update for my model JW. In fact i though I had the 201 ver but I misread that it is the 210 :). but as u said i think i ll contact them to see if any other update was released.
For the Win 8.1 I think i ll wait or even not upgrade. I read so many bad expériences around that I prefer not to.
In fact i'm planning on installing Win7 as dual boot with my Win8: but for this i need patience and a full day free of children and work responsibility which I lack of this moment 🙂
Rather than putting effort into going backwards, perhaps take the time instead to clone your boot drive, and set the original aside, and work on the copy, upgrading to WIndows 8.1, and if nothing goes wrong - which it likely won't - you would be at 8.1 - with a backup should anything come up as incompatible down the road.
Unless you have hardware, like a USB headset, that is known incompatible with Windows 8.1, there isn't much I have run across that won't work just as well on Windows 8.1 - and now that all the hardware drivers for Windows 8.1 are out, everything seems to be go for recommending upgrading to Windows 8.1.
If you have anything specific you found that you are worried about, post the link(s) here and we can take a look - someone probably has gone through it already and has a solution.
You could also do a Windows 7 Virtualbox / Vmware container and host it on Windows 8.1, so you could have the best of both worlds at the same time. That is what I do - I have a number of VM's - mostly Linux - to use while hosted on Windows 8.1.
Don't forget to do an Asus Backtracker backup of your Windows 8 recovery partition, if you haven't already.
Let us know what you work out, and how you like it 🙂