Mine was having he exact same problem. All I did was hard reset it, wipe the cache, and wipe the media partition.

First, turn off your nextbook.
Hold both the POWER button and the VOL UP button until the screen the screen comes on. Once its on, you can remove your finger from the POWER button but still keep it on the VOL UP button until the screen goes to a black BIOS screen.
From there, use the VOL DOWN button to scroll to the "Factory Reset/Wipe" option, then press POWER to enter.
Scroll down to Yes to confirm once more and that should be it for the Factory reset.
I recommend you proceed to the "Wipe cache" & "Wipe Media partition" options to be on the safe side.
I hope this solves your problem like it solved mine.