i just joined this forum in hopes of learning new things and getting a problem solved , I have a nextbook 8 with android 4.2 jelly bean . 8gb internal storage and micro sd card slot expandable up to 64 gb . i have used a samsung evo64 gb micro sd card and also a sandisk ultra 64 gb and when they are mounted it doesn't show up even after in the storage area (in settings) i push the sd card / mount storage . all i have on the 64 gb card is music videos from youtube . i can put in a 32 gb sd card with same stuff and it will show up on the external sd card showing how much and i can go in to external sd file system and all the video songs are their . i want to solve this problem as i want to have 64 gb space available like it says a person can do . i have tried reformatting the micro sd card from ntsf to exfat32 and back , makes no difference . i have also tried resetting my tablet to factory settings . could this be a bad tablet not allowing 64 gb micro sd cards ? i have it under warrantee .