(Help!) Clean OSX Install - Display Resolution Issue OSX UTILITIES ...

Hi,
I'm trying to Install Mountain Lion - from USB stick (Mac Pro 5.1)

Step One: I,m restarting OSX with "Option key" pressed - OK

and then I see OSX UTILITIES mode in two small windows (duplicated) - with resolution of tamagotchi - in purple colour.

MAYBE SOMEBODY COULD HELP ME WITH THAT? - Please.
(It's my first MAC and First thread on Mac forum.)

Here's this screen picture:

Many thanks
Chris

Mac Pro 2009 - firmware update 4.1 to 5.1, 12 core (updated from 8 core)
graphic card gt120 (512mb)
OSX El Capitan 10.11.5

P.S.(also I had problem witch setup display resolution 1680x1050 on gt120)