My computer won't boot up

Hello,

The CPU is working (it is blinking when reading), the monitor light is working, the fan is working, keyboard is working (lights on).

Once we turned on our computer, the windows logo appear with the matching sound of windows, right?

Not in my case, once i turned on my computer, everything works except for the monitor, it has no display. I know that windows is already open because of the sound when the logo appeared.

i always waited for 15 to 30 minutes everytime i open my pc, then restart my computer, sometimes it works, sometimes not and this is breaking my nerve . . . . the cpu is just barely 2 months since we purchased it.

Please help. Thank you so much.