I've just updated my 10 year old desktop to version 2004 from 1903. Version 1909 was waiting from windows update but I thought I'd try version 2004 using the Update assistant from
https://www.microsoft.com/en-gb/software-download/windows10 took about 1.5 hours without problems. Hardware was confirmed as okay by the update assistant so I carried on. (using it now)
Spec of custom PC
Asrock MB P55M Pro with 1st gen i5 750
Nvidia GT 710
8GB memory
3 HDD.
Connected via ethernet.
It might suggest you have something in configuration, software or drivers causing a problem.