I upgraded 7 machines to 1607. All of these machines are running 1511, 3 of the machines had 32-bit versions (1 Asus transformer, 1 Asus Tablet and 1 HP Stream Tablet). All these machines upgraded and migrated without any issues.

Of the remaining 4 machines, 2 are Intel based (Xeon 1241 and i5-4570) and 2 are AMD based (FX8350, X6-1100). The Xeon machine originally came with Win8.1 retail and the FX8350 with Win7 Home Premium. Both these machines migrated without any issues as well

The two last machines (the i5-4570 and the AMD X6-1100T) are the ones that I am having problems with. I originally updated the machines to 1607 via streaming (windows updates). The AMD machine initially seemed to have installed properly but opening my computer just gives me the "working on it" message and it never opens. I reverted to Win10 1511 and tried installing via iso and it appears to proceed normally until I get to the point where it says "machine will start in a few moments" I waited 3 hours and it is still stuck on that screen

The i5-4570 machine offers a similar behavior. Everything seems to install properly until I try and browse my computer. I get the "working on it" message and nothing happens. Again, I upgraded this machine via windows update. Didnt work. Reverted to the old OS then tried an upgrading via iso. Same behavior. Unable to browse any folder and some programs are stuck, wont open / wont launch

All these desktops have similar configurations. SSD for boot and OS. HDD for storage. The hard drives were disconnected during the upgrade process since they only contained files and docs. All the desktops have 16GB of memory and using a dedicated graphics card. Power supplies are all quality Corsair AX/HX models. All drivers and updates were applied prior to upgrading. The only commonality between the two machines that wont complete the upgrade to 1607 is that they both originally had Win 7 Ultimate as their original OS. I am not sure if that makes a difference. Right now, Im doing a fresh / clean install on the i5-4570 and will see if that makes any difference. However, for the time being, any input as to why I am having issues with these two machines would be appreciated