Chuwi hi8 only support Android 4.4 and windows OS. You can’t update to Android 5.0 now. But It is not impossible. I was told that it may be updated in future from Chuwi staff on Chuwi Official forum.
If you don’t need Android OS,you can delete it. But you can’t delete Windows OS.
The right driver can be download from Chuwi Official forum ( i think it is the most official ), including firmware, Bios, driver, tutorial,etc.
http://forum.chuwi.com/forum-51-1.html