A poet friend's Windows notebook ceased working and Windows could not get up again. A couple of days work did not result in a working system. He was going to solve the problem by buying a new machine. I volunteered to attempt to fix his machine. I investigated the system (using a live Fedora stick). I found that his files were gone and that the disk wasn't 100% happy. I fixed it by copying /dev/zero to the whole raw drive. (There were 8 relocated sectors, not a strong sign that the disk is deteriorating quickly.) Whereas before my fix, a short drive-self-test failed, afterwards it passed. The next step was to make a bootable Win 10 installation disk. A bootable Win 10 installation disk is not as simple as a bootable Linux disk. It won't perform as a Live system. It isn't made by dding a .iso to the USB flash stick. On another Windows box, download the Media Creation Tool. Run it, asking it to create an installation stick. It downloads Windows, and uses the files to build the installation stick. This failed for me. I'm not alone. There are many postings by confused users. I found many many suggestions of work-arounds, but no convincing theory that any of them worked. At the start of this thread, you'll see the truly useless error pop-up: <https://answers.microsoft.com/en-us/windows/forum/all/media-creation-tool-error-0x80042405-0xa001b/48b2c661-c065-4b1e-b103-d41d029dcb13> Windows 10 Setup There was a problem running this tool We're not sure what happened, but we're unable to run this tool on your PC. If you continue experiencing problems, reference the error code when contacting customer support. Error code 0x80042405 - 0xA001B There is no evident customer support. Just fora full of ignorance. This problem (or at least this symptom) has been around for years. For no good reason, I reformatted the USB stick and ran the MCT again. And it worked. At the cost of having downloaded all of Win 10 twice. MCT is too stupid to save its work. Evan may like Windows, but my modest experiences with it are often unpleasant. Now I'm onto the pleasures of installing Win 10 on a slow machine without an SSD. This is an area where Linux is much much more streamlined.