My main PC won't upgrade it's Windows 10 build - it downloads the build from Windows Update (I've tried this with 10147; 1015; 10159 and now 10162) and starts the upgrade process. It will then reboot and get as far as 28% completed (80% file copy stage) where it hangs / physically crashes and won't go any further. It has now been left for 36 hours to check it wasn't just being slow. However, if I burn the ESD to a DVD (obviously via an ISO conversion) and do a CLEAN install to the same HDD partition, it will install fine and keep my existing documents; but obviously being a clean install trash all my applications etc. I've disconnected all external USB devices and even uninstalled the graphics card driver before trying the upgrade, but nothing seems to work. Has anyone else seen this issue?