My tablet won't download anything (market,blackmarket,online) and
I can't put thing on my sd card also those are the biggest problems
So far.

Model:M9100
Ver. 4.0.4

Did a factory data reset because screen froze and I shut down it and reboot it
Up but all it did was remove most all my apps and files.

1 - Try updating the unit.
2 - Try a different internet connection. Sim card or wifi vice versa.
3 - Still not working. Take the unit back to the place of purchase.

Hope this helps
Grant