If I was you, I would simply disconnect any add on drives, making sure that you had an ISO image of the new Win 8 DVD, then perform a clean install - the only thing after that would be to connect your additional hard drives one at a time to make sure that you get them in some sort of order you want. Turn off the system restore, move the pagefile to a spinner drive and not an SSD, switch off Hibernation, and the rest - leave well alone and just see how well it runs.
As I said in an earlier post, the advice about editing the registry and fiddling with services is completely contrary to what both Microsoft and Intel advise - Superfetch and Prefetch do not work as they did on Win 7 - some of the advice here is just some cut and paste **** from a previous Win 7 OS install! READ what Microsoft and Intel advise before you go changing and pissing with registry entries and services. This is the most stable system I have ever installed from the word go - it needs very little "fiddling"on our part, it does mainly what it is supposed to do!