Default [Q] Galaxy ace 2 I8160P memory problem.

I just did a fresh cyanogemod install with erverything cleaned, have almost nothing installed and memory is almost full.

I see on storage :
System : 550 / 1000 Mb occupied.
Internal Sd : 950 / 1100 occupied.

How much memory does this phone have ?
How can i access system partition ? It does not show up in windows explorer nor in internal file explorer.