Default stuck on loop boot

hi,
when i turn on my tablet it looks like that:

https://www.youtube.com/watch?v=O0bccgMKDuA

my tablet is asus tf300t.

but here is the thing, when I insert sd card in it it works just fine, why?
i don't want the SD card in the tab. i want the tab to work fine without the sd in it.

thank for the help!