I do computer repair on the side, and recently was asked to "clean up" a windows 10 alienware laptop, (maybe 2 months old)
It was crawling, spyware, malware, telemetry. I couldnt open a command prompt, let alone a web browser.
In the interest of time, the client was okay with doing a fresh OS installation.
I created a windows 10 installation USB using the Microsoft tool, and booted into it. Cleared all of the partitions and created one big partition, minus the automatically generated 100mb windows boot area.
The installer detected the product key automatically.
While installing I selected turned every option to "off" and "skipped" everything else. This also allowed me to create a traditional login name, rather than an email address.
Once in the system I did my normal tweaks: turn off "slide" and "fade" options in Advanced System Settings. Forced explorer to show all file extensions and hidden folders, and make the task bar only collapse applications when full.
I unpinned everything from the start menu, hid a bunch of the menu links like "Music" and "Pictures", and uninstalled many of the preinstalled programs including the Office 365 Advertisement.
I also chose to use Smart PC Utilities' "PC Services Optimizer" and ninite.com to install firefox, chrome, teracopy, windirstat, 7-zip, java, foxit, and libre office.
Created a restore point and delivered the product.