I have both USB Installation Key combination 32/64bit Pro made up with the MS Media Creation Tool and the combination 32/64bit iso downloaded. The initial attempts for the upgrade which apparently can't be done by flash drive resulted in seeing a black screen following the initial system restart and getting past the startup logo screen when all goes dark. A subsquent pop up appears aftet the reset button was pressed indicating a failed install with an error and the system being reverted back to the previous state.
The second attempt was to boot live from the flash drive which still ended up seeing the exact same problem stalling after the logo screen upon the first restart. I will try again with a flash drive key made up using a 3rd image to flash drive program previously used for 7 beta, RC, RTM and the 8 CP not having later gone with 8 or 8.1. 10 looked a lot more interesting having waited a couple of versions for them to get the dual platform bugs worked out as well as seeing the Star menu return and the new Virtual desktops feature.