If it's brand new and you don't have any data You can simply use Dell's Cloud RESET feature and get the latest OS build.  F12 >> SupportAssist OS Recovery > RESET > RESET and update.    In case you still wanna troubleshoot.  : Pause windows updates from the same page  and reboot  : Download Microsoft Media creation tool [URL] : Choose create installation media for another PC  : Choose ISO and a location on computer to save it : Once download is finished, please double click on ISO file  : run setup  : Choose upgrade this PC now.   
Brand new XPS 9310, does not install any Windows updates, always returning 0x80248007 &  0x800f0900 errors [IMAGE]
WIndows updates to 20H2 fail with 0x80248007