Marcin360: You can try lowering the graphic settings in game's Launcher. Sometimes, auto-detection enables higher display options which can cause frequent crashes.
If problem still exists please turn off "Depth of field" and "Blur" option in graphic settings and follow instructions below:
1) Proceed to start -> run and type: cmd
2) In opened window type command: bcdedit /set IncreaseUserVa 3072
3) Restart PC
Well that was fast! Hmm you got me thinking maybe I should delete my custom config files and save files and start over with a clean slate so to speak. I'll try what you suggested when I get home. Hope it works :)
EDIT: So far so good, about an hour without a crash (usually it crashed when I quicksaved). This time I adjusted settings from the *configurator* to sensible levels. I let you guys know if my good luck continues.
EDIT: OK no crashes anymore and I experimented a bit with User.ini and got the game looking wonderful (and with FPS between 30-60).