Help! i have a problem whit zorin os lite

Hi, I have installed zorin os like 2 weeks ago, my laptop is a acer aspire 7720g.
Zorin continue freezing and crashing!
When i search on internet, when i use paint,
zorin continue freezing and it obliges me to do a hard shutdown .
Some solution?
When it freeze the color turn like this:

Can you list your Graphics cards?

Can you monitor your Running Temperatures while using the computer, looking for overheating?

To provide information for us to help diagnose the issue, please do the following...

CTRL ALT T to enter terminal

sudo apt install screenfetch

Press Y when prompt, then once finished.
Type screenfetch Please post results here.

In regards to thermals, please install Psensor...

sudo apt install lm-sensors
sudo apt install psensor

Press Y when prompt.

Now, you should be able to find and launch Psensor by clicking on the Zorin :zorin: logo at the bottom left of the screen, type Psensor, click on it. Now, take a screenshot by clicking on the Print Screen key on your keyboard.

Please post the screenshot here.

I have a nvidia geforce 8400M GS 256 mb

I can't do it, the system crash before I do it

Can you boot normally? If so, remove nvidia and run only on the onboard intel graphics for a time.

sudo apt remove nvidia-*

Test for any freezing or discoloration. If there is none, then we know that it is the Nvidia Graphics drivers that need to be addressed.