It is usally because these low cost computers often come with a user account already installed on your computer and usually that means someone was on it installing things such as malware. Also its usually in Chinese, so by fresh installing Windows 10 you remove all malware, remove the account put onto the computer by the Chinese and set it to your home language.
Yes it is possible to reinstall with the Microsoft ISO (thats what I did). Afterwards you must reinstall all of the drivers, which I’m having a few problems with (only the audio is still a problem).