New PC error, please help.

[Snowyy]

I bought a new PC two days ago and I've been having this bug which I just cannot figure out how to solve; hoping someone here could help.

To sum it up, the PC will randomely turn itself off and restart itself sometimes, however once it turns back on again the resolution changes from 1920x1080 to 800x600 and refuses to let me change it back unless I restart the PC at least three times.

 

[Colif]

I bought a new PC two days ago

If its a new pc, take it back. you shouldn't be having problems like that after 2 days. Get the people who made it to fix it.