I have not tried it, so this is a complete guess. The two things I would wonder (both seem equally important): First, have you tried using the key like F10 immediately after power on and be sure that you are booting the desired mode such as UEFI for the USB or DVD? Second, whether you see the screen like previous versions of Windows where it shows the disk and any partitions, and I always delete each of the partitions until there is only unpartitioned space, and that is where I tell Windows to install.
Thanks for the reply.
I don't think the problem is with the disk partions as I formated the disk a couple of times.
I tried formating the disk under UEFI and Legacy.This might still be the problem though. Need to do more research on this. I think I was using Legacy all the time but it is worth checking.
Hi. I'll reemphasize what dougho said about removing the partitions. I wanted a clean install also. When I went to install Win10 a second time (after installing the upgrade over Win8.1), I removed all existing partitions (not just formatting the disks), directed Win10 Setup which drive to install on (I have both M.2 and 2.5-inch SATA), and Win10 Setup went ahead and setup several partitions on the drive.
Hope this helps!