I am no technician.
I never do preventative maintenance.
I don't have anti-virus(only Microsoft Defender).
The only time I experienced "FAILED Download - Network Error"
was after flawless performance for four years.
I could not find any reason. After basic diagnostics led nowhere, I resorted to turning off my computer and during the struggle of shutting down, I got a notification that Windows OS had urgent updates to install. I started the process and it took 30 minutes and three restarts(each w/ more updates) before the misery was behind me. I haven't had any more grief or missed downloads since then. It's been about two years!
I think I may blow the dust out of it next year. Also, use hard shut downs instead of restarts!
Open the pod bay doors HAL!
KC