Cannot use internal memory partition in my Nextbook 7 16GB tab
Every user of this tablet is having this issue. The company supposedly put out a firmware fix, but when you download the files to install it, they are corrupted. Which either means they are incompetent or purposely put out files that are corrupt so they can say "oh sorry" and never address the issue. Either way I'm not too optimistic.

http://nx700qc.blogspot.com/2014/11/trying-to-update-firmware.html?showComment=1417564996972#c1557705469401201898

http://www.nextbookusa.com/download.php