Instead of downloading drivers from HP Stream, use DoubleDriver to backup and restore the drivers
To retain original Windows license, it is better to upgrade first from current Windows 8 to Windows 10. Once upgraded, make sure you’ve logged in to your Microsoft account and make sure your Windows successfully activated. Then, reformat all and repartition all (if want to remove android) as suggested by this guide.
Download “wushowhide” to disable automatic Windows update for Intel HD Graphic drivers. There are newer version released by Intel and microsoft updates keeps revert back to the old version