When I turn on the tablet it says "Android upgrading" over and over and never turns on.
When android's cache is removed or deleted by user it will take time to to boot because it rebuilds all the cache for apps. Its time depends upon the number of apps installed. If you want quick start up you have to remove user apps before you boot your tablet. Press and hold (volume up + volume down + Power) buttons when switched off. You will enter into recovery mode. Here you can navigate by Vol - and + buttons and select by power button. So go to "Wipe data/factory reset" (apps that you installed will be deleted. Pics, files, videos will be safe). And reboot tablet, it will take some time to rebuild cache for system apps that are now less...
leave it running until the upgrade is complete, preferably with it plugged in to the mains and within range of your wireless router.
(I assume you've set up a WiFi connection on the tablet?).
When I turn on the tablet it says "Android upgrading" over and over and never turns on.
When android's cache is removed or deleted by user it will take time to to boot because it rebuilds all the cache for apps. Its time depends upon the number of apps installed. If you want quick start up you have to remove user apps before you boot your tablet. Press and hold (volume up + volume down + Power) buttons when switched off. You will enter into recovery mode. Here you can navigate by Vol - and + buttons and select by power button. So go to "Wipe data/factory reset" (apps that you installed will be deleted. Pics, files, videos will be safe). And reboot tablet, it will take some time to rebuild cache for system apps that are now less because user apps are deleted only system are remaining. And you tablet will start fine.
leave it running until the upgrade is complete, preferably with it plugged in to the mains and within range of your wireless router.
(I assume you've set up a WiFi connection on the tablet?).
He cant boot to system so connecting to WiFi is not possible as well as not required.