Why does my computer screen occasionally black-out?

Upgrade the video driver. It’s failing and then restarting.

i agree with @pdworkin also might be a sign that your graphics card is on its way out

I don’t know but this happens to my computer sometimes too!

I disagree with above. Everything is still there? It actually sounds like a backlight is on the fritz. If it was the driver, you’d see nothing at all, looking closely at it wouldn’t make a difference. Is it an LCD? If so, chances are the backlighting is going on and off, probably due to a wire being either out of socket or nearly worn through. Especially probable if you have a laptop.

All LCDs have a backlight which shines through the crystals, which move in various ways to show color and contrast. So, you need the backlight to really see them, but if it does out, the crystals themselves are still present and moving correctly, so you should be able to see it, like you said.

I think that’s correct. It isn’t the driver. I missed the bit about seeing the image.

i agree with @BhacSsylan . it is more than likely an LCD with a loose wire or bad connection on the diode.

OK, I got the new driver, but it has done it again after restarting. What else could be the problem?

@Fred931 It’s almost certainly the back light, then. Take it to a computer repair shop and tell them the details. They may be able to fix it. You won’t be able to without taking your computer apart.