Just some mentionable.

If upgrading from XP to Win 8, XP SP3 has to be installed. You may save files but you'll have to do a clean install. Your settings will be lost and you'll have to re-install the applications programs.

Only Win 7 can be upgraded without several problems and losses.

There are primary differences between Win 8, Win 8 Pro and Win 8 Enterprise.

WMC is extra money in Win 8 and Win 8 Pro.

All of this is missing in Win 8 *( Regular or OEM ).

* Presentation settings.
* Remote desktop host.
* Boot from VHD file.
* Hyper V Virtual Machine Manager.
* Bitlocker and Bitlocker to go.
* Domain Network Member.
* Manageable by Group Policy.
*App locker.
* Boot from USB drive.
* Direct Access *( automatic VPN to the office ).
* Installation of Windows 8 - style apps outside of Windows store.

* The last three items are also not in Windows 8 Pro, only in Enterprise.

The 64 bit versions of Win 8 Pro and Enterpise include Microsoft's Hyper- V machine manager *( VMM ). If you want to run virtual machines on 32 bit Windows 8 Pro or Enterprise you'll have to install VMware, VirtualBox or another VMM.

Further Microsoft had some sites blacklisted due to incompatibility. Just recently they reversed and white listed some.

As I read the posts here it occurs to me that there may be a fundamantal lack of undrstanding of what each version of Windows 8 contains. If some expectations don't occur as anticipated it could be due, in part at least, to not proceeding according to the steps outlined by Microsoft and Windows 8.