I did a few rebuilds this week of my Windows 8 RC machines to Windows 8 RTM. All went well, I didn’t do any upgrades from Windows 7, and honestly not sure I would. I generally like the clean break and don’t like to bring over any old stuff.
Couple things I found useful when doing the installs – first for the //Build Samsung Slate, I used a USB stick to boot from and install the RTM Windows 8 – that didn’t work too well the first time because I didn’t build it with a FAT32 and didn’t disable the UEFI – so despite my effort to get it to boot from the USB it would just ignore it – reading this post http://social.msdn.microsoft.com/Forums/en-US/samsungpcgeneral/thread/e7ed293e-b565-44ee-a536-166dddf32205/ I was able to re-build my USB and it worked fine.
Another thing that isn’t real obvious if you install the Windows 8 Enterprise edition it’s a little challenging to activate because it’s expecting to find a volume license server. For that used “slmgr” to set the key and activate it. So basically you go to MSDN, grab your key, from an elevated command prompt do a slmgr /ipk <your key here> that sets the key, then do slmgr /ato to activate your copy – you should see a message box confirming.