Computer will not boot

I was rebooting and got greeted with a black screen. Now it won't get past the initial start up screen. Nothing will boot.
What do i do?

Take out your kettle lead or turn it off it the mains, whichever is easier.

Wait a couple of minutes then turn it back on again. I would imagine it will boot fine but if not, we will need to isolate the problem.

"Initial startup screen" being what - the OEM logo/bios screen, the Windows welcome screen?
Is anything at all on this black screen?

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when that happened to me i found out it was my motherboard. if that is the case, replace it and get yourself a UPS box to plug your comp into.

Oh i forgot to add that the black screen only has a flashing underscore

Since you can get into the bios, if you have any cd/dvd that's bootable, I'd change the boot order and see if it'll boot from them. If that works at least then you know that the motherboard cpu etc are probably ok, I say probably since I've seen stranger things happen.

i'm telling you it is a problem with your motherboard. i had the same exact issues with my comp.

Have a card reader? Remove any memory cards. See if it boots.

Unplug power. Open the case. Unhook the DVD drive, and any hard drives other than the boot drive. See if it boots (obviously put power back first.)

If not, plug in the DVD (with a bootable disk,) make sure the DVD is set first in the boot order, and unplug the hard drive. See if it boots.

Plug both back in. See if it works now. (No, not a smartalec suggestion. Could simply be a connection issue.)

If neither work, and you're getting the same thing, unplug all drives, see if it gives you something simlar to a 'system disk not found.' If it still gives you just the line... >.<

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I had a similar thing happen a couple of weeks back. I looked it up on my wife's laptop, and everything indicated it being a motherboard issue. (Though some sources thought it was RAM)

I read stuff about (I believe it was called) POST procedures, wherein different beeps meant different things. Usually, my fan starts up, then a beep, then everything begins. It usually takes a few seconds. This time, my fans were going for over 3 minutes, then one beep... and nothing.

I tried plugging my monitor into my onboard graphics plug. It worked. (Albeit at a terrible resolution). I bought a sale video card on Boxing Day for $60, and it works just as it did before.

Things I was looking at said to make sure all of your wire harnesses are firmly plugged in. Try removing your RAM, and placing them in one at a time, in the event that one of your RAM sticks is bad.

Thank you, Champion.

Remove ALL USB devices before booting.

File this under strange but true:
I have had 2 USB devices do the same thing to me over the years. My Z-Board Fang had a stuck key once that cause the flashing cursor hang, and most recently my LG env Touch phone plugged in during reboot.