Zoostorm desktop pc wont start up

[Anne broadhurst]

Hi my son has this pc and he pressed reset in the settings because he was having problems with disc space.now when you turn on the computer it starts up but the monitor keeps flashing on and off and there's nothing, I've checked all the cables I've pressed f8 on start up,nothing, on thing that I can get up is bios by pressing ctrl alt delete. Please help.it's a new pc.

 

[Tmagic650]

Desktop or laptop computer?