This old laptop's been a pain with Windows 10. It runs fine with 7 Pro, 8.1 (as Enterprise trial), but upgrades are almost impossible, and until today, I could not clean install either.
The reason is the built-in wireless adapter and the Windows 10 driver for it or at least a problem in the way Windows 10 manages PNP IRQ sharing.
With the adapter enabled, there is an IRQ conflict, which stops as soon as the adapter is disabled, and the system interrupts drop down, freeing the cpu from 100% use and enabling everything to run at reasonable speed.
The problem is that Windows Setup causes the same Systems interrupt blockage, because there is no way to stop setup from enabling the device - being a laptop, I'd have to open it up and remove the adapter card.
The first time I installed Windows 10 in this laptop (about last Christmas) with any success was an upgrade from a Windows 7 Ultimate installation. It took ages, and I had already had many failures before since July 2015. I had to be very patient, and the installation was still damaged - I could not get the resolution setting of 1440x900 for the monitor I use to stick between restarts, but at least it activated.
Having used Macrium Reflect to image the installation I tried to reset, clean install, upgrade to newer builds etcetera, all failed, and I had to restore the Macrium Backup.
With Windows 7 and 8, I used to use Imagex to apply the install.wim image to the partition I had prepared and formatted, instead of using setup. This did not seem to work with Insider ESD downloads, so I forgot about it - but today I used an Iso downloaded from the Microsoft Iso site, with an install.wim, extracted it and booted up WinPESE 8.1, downloaded the Waik tools, and applied with Imagex to the partition I had formatted which had had the last Windows 10 installation on. I left the system partition alone, and after imagex had finished successfully, I rebooted, to finalise the installation.
As I half expected, it installed the devices fast enough, but then went slow during the "getting ready" phase, as it had enabled the wireless adapter, slowing it all up.
When It had been going awhile, an hour, perhaps, I hit shift+F10, to bring up the command console, and then called up devmgmt.msc, and once that had returned to the command prompt, called up taskmgr.
After a few minutes, taskmgr appeared, and switching to the details tab could see that System interrupts were running at 86-90% of the CPU use.
Eventually the MMC with Device Manager appeared, and eventually I could see the devices - and when I managed to disable the Atheros adapter, and confirmed the disable request, the setup resumed with reasonable speed, and I could complete the installation.
Now It seems as if the screen resolution remains as I want, and the old laptop goes as fast as it ever did with XP, 7 or 8.1.
I shall be sending a report to Feedback with these details, because there's some problem with Windows 10 and PNP management that does not exist in XP, Windows 7 or 8.x, and of course, there is no WER available when setup fails.