Have you tried changing the resolution in your config file manually?
I had the exact same problem some time ago after I installed DayZ.

Just change the values within the .cfg file to this:

Resolution_W=1920;
Resolution_H=1080;

and

Render_W=1920;
Render_H=1080;

At the moment your game runs at 320x240, that's why your Screen won't Show anything but a "8bit-ish "Wait a while"" and a "big DayZ logo with sound playing".

Hope this solves your problem