Backup / Upgrade OS


My Lenovo Tablet has full instructions for upgrading OS from 4.4.2. I am however a bit nervous and I would like to know

1. Can I back up OS before upgrade
2. If there are problems with upgrade will I be able to convert back to original

If the answer to both above is yes then some general guidance on how to proceed would be appreciated


Spacecorp test pilot
The answer to 2 depends on the manufacturer, which I can't answer for Lenovo. But the answer to 1 is no, unless you have a custom recovery in which case the official over-the-air update doesn't work on most devices (if you don't know then you don't have a custom recovery).