Don't change config file
1)Reduce resolution to 800*600
2)CPU buffering to 2
3)Detail level to high
Other to low or off
4)use light antivirus
Now edit configuration file:
1)Change all words from PC to console except
Road
2)High precision normal=0
3)Make 1 to 0 whatever possible
This will prevent shutter by gradually applying
Mild load on CPU
If u keep all settings low, sudden load will applied
Result in shutter