It's a really awful way to start a day: you press the power button on your computer and nothing happens.
There are many reasons why a computer won't turn on and often very few clues about what might be the problem. The only symptom is usually the simple fact that "nothing works," which isn't much to go on.
An illustration of a computer that won't turn on.
Here's what you need to do:
Read Step 1 below! Trust us, it'll make you feel better.
Pick the best troubleshooting guide from Steps 2 through 9 based on how your computer is acting or choose Step 10 if your computer stops at any point because of an error message.
The troubleshooting guides below apply to all PC devices. In other words, they'll help if your desktop or laptop won't turn on, or even if your tablet won't turn on. We'll call out any important differences along the way.
These techniques are applicable no matter what Windows operating system is installed, including Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP. The first five steps even apply to other PC operating systems like Linux.
Your files are probably OK. Most people tend to panic when faced with a computer that won't start, worried that all their precious data is gone forever.
It's true that the most common reason a computer won't start is because a piece of hardware has failed or is causing a problem, but that hardware isn't usually a hard drive, the part of your computer that stores all of your files.
In other words, your music, documents, emails, and videos are probably safe—they're just not accessible at the moment.
If you don't want to fix this yourself, see How Do I Get My Computer Fixed? for a full list of your support options, plus help with everything along the way like figuring out repair costs, getting your files off, choosing a repair service, and a whole lot more.
Computer shows no sign of power. Try these steps if your computer will not turn on and is showing no sign at all of receiving power—no fans running and no lights on the laptop or tablet, nor on the front of the computer's case if you're using a desktop.
Here's What to Do When Your Computer Has No Power
Don't worry about the monitor yet, assuming you're using a desktop or an external display. If the computer won't on because of a power supply problem, the monitor certainly can't display anything from the computer. Your monitor light will likely be amber/yellow if your computer has stopped sending information to it.
Computer powers on and then off. Follow these steps if, when you turn your computer on, it promptly powers back off.
Here's What to Do When Your Computer Shuts Off During Startup
You'll probably hear the fans inside your computer turn on, see some or all of the lights on your computer turn on or flash, and then it will all stop.
You won't see anything on the screen and you may or may not hear beeps coming from the computer before it shuts off by itself.
Like in the previous scenario, don't worry about the state your external monitor is in, if you have one. You may have a monitor problem as well but it's not possible to troubleshoot it quite yet.
Computer powers on but nothing happens. If your computer seems to be receiving power after turning it on but you don't see anything on the screen, try these troubleshooting steps.
Here's What to Do When Your Computer Starts but Nothing Happens
In these situations, the power lights will stay on, you'll likely hear the fans inside your computer running (assuming it has any), and you may or may not hear one or more beeps coming from the computer.
This situation is probably the most common in our experience working with computers that won't start. Unfortunately it's also one of the most difficult to troubleshoot.
Computer stops or continuously reboots during the POST. Use this guide when your computer powers on, shows at least something on the screen, but then stops, freezes, or reboots over and over again during the Power On Self Test.
Here's What to Do When Your PC Freezes During POST
The POST on your computer might occur in the background, behind your computer maker's logo (as shown here with the Dell laptop), or you may actually see frozen test results or other messages on the screen.
Don't use this troubleshooting guide if you encounter a problem during the loading of the operating system, which occurs after the Power On Self Test is complete. Troubleshooting Windows-related reasons why your computer won't turn on begin with the next step below.
Windows begins to load but stops or reboots on a BSOD. If your computer begins to load Windows but then stops and displays a blue screen with information on it, then try these steps. You may or may not see the Windows splash screen before the blue screen appears.
How to Fix a Blue Screen of Death
This kind of error is called a STOP error but is more commonly referred to as a Blue Screen of Death, or a BSOD. Receiving a BSOD error is a common reason why a computer won't turn on.
Choose this troubleshooting guide even if the BSOD flashes on screen and your computer restarts automatically without giving you time to read what it says.
Windows begins to load but stops or reboots without an error. Try these steps when your computer powers on, starts to load Windows, but then freezes, stops, or reboots over and over again without generating any kind of error message.
Here's What to Do When Your Computer Freezes During Windows Startup
The stopping, freezing, or reboot loop may happen on the Windows splash screen (shown here) or even on a black screen, with or without a flashing cursor.
If you suspect that the Power On Self Test is still going on and that Windows has not yet started to boot, a better troubleshooting guide for why your computer won't turn on might be the one from above called Computer Stops or Continuously Reboots During the POST. It's a fine line and sometimes hard to tell.
If your computer won't start and you see a blue screen flash or remain on the screen, you're experiencing a Blue Screen of Death and should use the troubleshooting guide above.
Windows repeatedly returns to startup settings or ABO. Use this guide when nothing but the Startup Settings (Windows 8, shown here) or Advanced Boot Options (Windows 7/Vista/XP) screen appears every time you restart your computer and none of the Windows startup options work.
Screenshot of the Startup Settings menu in Windows 8
Solutions for a Computer That Won't Go Past the Startup Options
In this situation, no matter which Safe Mode option you choose, your computer eventually stops, freezes, or restarts on its own, after which you find yourself right back at the Startup Settings or Advanced Boot Options menu.
This is a particularly annoying way in which your computer won't turn on because you're trying to use Windows' built-in ways to solve your problem but you're getting nowhere with them.
Windows stops or reboots on or after the login screen. Try this troubleshooting guide when your computer powers on, Windows shows the login screen, but then freezes, stops, or reboots here or anytime after.
What to Do When Windows Freezes During or After Login
The stopping, freezing, or reboot loop may happen on the Windows login screen, as Windows is logging you in (as shown here), or any time up to Windows fully loading.
Computer doesn't fully start because of an error message. If your computer turns on but then stops or freezes at any point, showing an error message of any kind, then use this troubleshooting guide.
hal.dll Error Message
Here's What to Do When Your Computer Stops With an Error Message
Error messages are possible at any stage during your computer's boot process, including during the POST, at any time during the loading of Windows, all the way up to the Windows desktop appearing.
The only exception to using this troubleshooting guide for an error message is if the error is a Blue Screen of Death. See the Windows Begins to Load but Stops or Reboots on a BSOD step above for a better troubleshooting guide for BSOD issues.