Your first reaction when you find your PC won’t boot is probably panic, but the problem is often not catastrophic. It is probably a trivial and easily solved technical problem.
There are many reasons why your computer won’t turn on and many definitions of “won’t turn on”, ranging from “nothing happens” to “Windows won’t start properly”.
How to troubleshoot your Windows PC when it won’t turn on
Below are the 10 most common solutions to get your computer working with that spectrum of problems in mind.
Try a different power source
If you try to turn on your computer and absolutely nothing happens, there are generally only two possibilities. Either the internal power supply of the computer has failed, in which case it probably needs to be replaced or there is no electricity entering your PC.
Unplug the computer from wherever it is currently plugged in and plug it directly into a wall outlet, bypassing the UPS, surge suppressor, or power strip. If still nothing happens, make sure the outlet is working by plugging in something else, like a desk lamp, and confirming it turns on.
Try a different power cord
This is highly unlikely, but it is an easy fix. If you have a spare power cord available, replace it. If the original cable is broken, the computer should restart with the new cable.
Let the battery charge
If the computer that’s not working is a laptop and you’ve recently run out of computer, it’s not uncommon for it to fail to boot even though it’s now plugged into wall power. Plug in your laptop and let the battery charge for at least half an hour. Then try turning it on again.
Decipher the acoustic codes
Some computer motherboards emit a series of beeps upon startup. A single beep can signal that all is well, while a long, continuous beep could indicate that the power supply has experienced a critical failure.
There is no single standard set of codes, but beeps can sound like Morse code, with long and short tones. Check your computer’s user guide, website or support service technician to understand what the error is pointing to.
Unfortunately, not all motherboards use beep codes either, so this may not be a viable option.
Check your display
If your computer seems to be working, or at least is making noise, but nothing appears on the screen, make sure the monitor is turned on and connected to the computer.
It’s also worth checking to make sure the brightness hasn’t accidentally been set to zero. If that’s an option, try connecting the computer to a different display to see if that fixes the problem.
Check your BIOS or UEFI settings
If your computer appears to be doing something but is not starting Windows, there are several possibilities as to why. It starts with the computer’s BIOS (Basic Input / Output System), which, in most modern PCs, has been replaced with much less friendly sounding UEFI (Unified Extensible Firmware Interface).
You may need to check your computer’s user manual to find out which specific key to press to enter the BIOS or UEFI. You may also see on-screen instructions at startup telling you which key to press. But regardless of how your PC is equipped, here’s how you should be able to access the BIOS or UEFI.
1. Turn on your PC.
2. Immediately press the computer-specific start key; Common keys include ESC, Delete, F1, or F2.
Once you’re in the BIOS or UEFI, make sure your computer is configured to boot from your primary hard drive, disable Fast Boot, and look for any other unusual settings that may be causing boot issues. You can also reset the BIOS or UEFI to factory settings and see if that fixes the problem.
Try Safe Mode
If you can access your computer’s BIOS, you may also be able to access Windows special boot options. If possible, start your computer in safe mode. It can be tricky, so here’s how to do it.
1. If there are any power lights or activity signs, press and hold the power button for 10 seconds to turn it off.
2. Press the power button to turn on the PC.
3. Look closely and at the first sign that the computer is starting up – generally, you will see a logo on the screen – hold the power button for 10 seconds to turn it off again.
4. Turn it on and off for a total of three times.
5. When turning on the fourth time, let the computer stay on. It will enter the Windows recovery environment.
6. On the “Choose an option” page, select “Troubleshoot”.
7. Select “Advanced Options”.
8. Choose “Startup Settings”.
9. Awards “Restart”.
10. When your computer restarts, select “Safe Mode with Networking” from the list of options.
If your computer starts up normally, try undoing any recent changes made to the computer. This may include uninstalling recently added hardware. You may also want to reset your computer to a clean install of Windows using the “Reset this PC” section of Windows Settings.
Disconnect anything that is not essential
A basic rule of thumb for troubleshooting is to eliminate as many variables as possible. So, if you have tried the previous solutions and it is still not clear what is going on, unplug everything that is not absolutely essential from your computer. This generally means removing the printer cable, scanner, webcam, and anything else connected to the computer. Now try starting your computer with just the power cord, monitor, mouse, and keyboard.
Make sure nothing has come off
While something loosening might be a relatively rare problem, it’s still worth fixing.
You can do this by removing the side panel of the computer and, with the power unplugged, making sure everything is still seated correctly. For the most part, that means inspecting the video card, sound card if you have one, memory chips, and all power and data cables.
Check for ransomware or viruses
If your computer is clearly starting up but does not boot properly into Windows, your computer may be infected with malware, such as a virus or ransomware. Badly written malware can be faulty enough to prevent Windows from functioning properly.
Try booting your computer not from the internal hard drive but from a USB drive. If you can get your computer to work properly this way, you can use anti-malware software to inspect your PC for unwanted software.