I have a Nokia Lumia 520 that I bought used. When I began using it it told me there was a new OS update to be installed. I did that. But after it runs for some amount of hours it will again tell me that there is a new version of the OS to be installed. Is there something I can do to get it to stop re-updating?
Uncheck 'Automatically Download Updates' option under Settings > Phone Update, if you do not wish to download updates automatically. You can manually check for updates using 'Check for Update' and install when you wish to.