For Those stuck in a restart loop because of the update -
you have to uninstall graphic drivers (or disable graphic card ) this is a copy paste from another post of mine
Basically i would get the loop before the update because of dual video cards
"
GUYS I FOUND A SOLUTION ! at least in my case
From what I am able to tell this happens because there is some sort of conflict between your current drivers and Windows 8 ( or dual video cards in my case).
This solution works once you reach the Windows 8 screen - do not update
press windows button + r -> this will pop up the run window --> type msconfig --> which will bring up the system configuration window ---> here go to the boot tab --> tick SAFE BOOT at the bottom and make sure it is set to Minimal --> then click OK and
restart --> This will restart your computer in SAFE MODE !
Once in safe mode uninstall your video card drivers (if you think audio drivers is what causing the problem then those as well) this should normally do the trick --> if you are like me and have 2 graphic cards (HP pavillion dv 6 - one for better performance
while plugged and one for battery) then go into Device Manager ( put the mouse into left corner and right click) go to display adapters and disable one graphic card (does not matter which one).
Even if you have one graphic card I think its worth disabling it - as it will get automatically swittched on later (read till the end)
If you don't know whether you have 2 graphic cards or not then just follow the steps above and once you Reach Display Adapters if you have 2 names then there are 2 if its just one you have to follow the below steps
Ok so having uninstalled the graphic drivers go the Run windows again (windows button +r ) type msconfig again and in the Boot tab untick the Safe Boot Box click ok and restart.
Basically now do the windows update - should work fine after which install your graphic card drivers as administrator and in compatibility with windows 7 ( drivers have to be meant for windows 7 ) once the drivers are installed it will automatically enable
your graphic card is you chose to disable it.
To do this right click the driver exe file ( which you should have on a disk and if not just download from your laptop manufacturer's website) go into Proprieties -> Compatibility TAb -> tick run this program in compatibility mode for (select) windows
7 and then go at the bottom where it says Run this program as an administrator ---> tick the box click ok and install..
That should be it. Like I said this worked for me chances are it will work for you as well but as I am not part of Microsoft staff or any IT company for that matter I can not guarantee it will work.
Best of luck as I will now proceed to enjoy my windows 8 after 5 days of struggle and 5 re installs
P.S.
If when you are reading this you are in Windows 7 with all you're files intact please back up : ) "
Hope this helps