How to Fix a PC Which Won't Boot
Try to turn on the computer., Click one of the following links based on what happens., Check the power cable., Remove your laptop's battery and connect the power adapter., Try a different monitor., Open the computer., Check your power supply...
Step-by-Step Guide
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Step 1: Try to turn on the computer.
The first step to determine what you'll need to do is to try to turn the computer on. , No response
- Click here if you can't hear any fans starting and can't see anything on the screen, or the computer starts for a moment and then freezes or turns off.
Beep code or POST failure message
- Click here if your computer doesn't pass the POST (Power On Self Test).
This is usually indicated by the lack of a beep and a failure message, or by a series of beeps to indicate an error code.Operating System Not Found or BOOTMGR is missing
- Click here if your computer completes its startup sequence but fails to load Windows. , It may seem simple, but double-check that the power cable is plugged in and the outlet is working.
Plug the computer directly into the wall to see if your surge protector or power strip is the cause of the problem.
If you are using a laptop, make sure that the power adapter is securely connected. , You can run your laptop without a battery inserted as long as you are plugged into a power source.
If your laptop turns on when the battery is removed, something is wrong with the battery and you should contact the manufacturer for a replacement. , If your computer is starting up but you can't see anything, there could be something wrong with your monitor.
Double-check the monitor's connection, and try plugging in a different monitor if possible. , In order to check the connections inside and to test the power supply, you'll need to open the case.
Click here for detailed instructions.
Remember to ground yourself with an antistatic wriststrap or by touching the exposed metal of the case before touching any internal components. , Ensure that the cables that connect your power supply (the box that your power cable is attached to) to your motherboard are securely connected. , Old power supplies have a tendency to fail, but testing them is a relatively straightforward process.
Power supplies are the most common cause for problems with a computer's boot sequence.
Click here for detailed instructions on testing your power supply. , If your power supply doesn't work after testing it, you'll probably need to replace it in order to get your computer working again.
Click here for detailed instructions. , If a screw has come loose in your case, it could be causing your motherboard to short out.
Gently rock your case back and forth and listen for metal rattling.
Either use your fingers or a long pair of tweezers to remove the screw from the case.
Look for any cables that have lost their protective coating, as exposed wiring may be causing a short as well.
Replace any cables that have decayed too much. , If you're "lucky"
your computer will issue a series of beeps when it fails to turn on.
Look up your motherboard's manufacturer and find the beep code translations.
Knowing what the codes mean will make tracking down the problem much easier.Beep codes are unfortunately different for every manufacturer, so you'll need to search for them yourself.
Click here for instructions on identifying your motherboard. , If you can, try entering your BIOS settings menu as soon as your computer starts.
Typical BIOS setup keys include F2, F10, F11, and Del. , Your BIOS will display all of your connected hardware in the MONITOR, HARDWARE, or SYSTEM section.
Check to see that your hard drive is displaying properly.
If your hard drive is not showing up, try replacing the cable inside the computer. , In order to check the various components inside the computer, you'll need to open the case.
Unplug everything from the back and remove the side panel to access the internal components.
Click here for detailed instructions.
Remember to ground yourself with an antistatic wriststrap or by touching the exposed metal of the case before touching any internal components. , Open up your computer and reseat your graphics card, RAM modules, and all of your cable connections.
If anything has come loose, there's a chance that it's disrupting the POST sequence.
You can try reseating your processor as well, but this is usually a much more difficult task, and likely isn't the cause of the problem.
It also increases the chances of damaging the processor, which will render your computer completely inoperable. , There's a chance that a bad memory module is causing your computer to not boot.
Try removing memory modules one at a time and booting your computer to try to isolate a bad memory stick.
You can run a utility like Memtest86 to help determine which of your memory modules is failing. , If you have a dedicated graphics card, try removing it and plugging your monitor into your motherboard's display connection.
A malfunctioning graphics card can cause your computer to not boot.
This article on installing graphics cards will give you detailed instructions on removing your graphics card. , Try booting your computer up with only the most basic hardware attached.
This means disconnecting your graphics card, additional drives, PCI expansion cards, and extra RAM.
After you've removed everything, try turning your computer on.
If your computer works with only the essential hardware installed, add pieces back one at a time, testing each time to see where the problem lies.
If you still cannot pass POST with just your essential hardware, then you'll need to either swap out the essential hardware with spares, take your computer to a repair shop, or upgrade to a new one. , If you are having problems loading Windows, you can try to fix it using Startup Repair.
This is accessible from the Advanced Startup menu if you are using Windows 7 or later.
If you are using Windows Vista or XP, you'll need to boot from the installation disc to access the Startup Repair tools.You can open the Advanced Startup menu by repeatedly pressing F8 as the computer starts up.
If you can't access the Advanced Startup menu, you may have a problem with your hardware.
See the above sections for troubleshooting your boot issues. , You will have to wait a few moments while the necessary files load. , You will be prompted to log in before you can start the repair process. , Windows will scan for problems related to booting the operating system and will attempt to fix them automatically.
Your computer will likely reboot during this process, possibly multiple times.
If Startup Repair fixes something, it is highly recommended to run it at least two more times before trying to boot normally.
Chances are it will fix something else when it runs again., Startup repair may suggest performing a System restore, or you can select it from the main Repair menu.
System Restore will provide several dates that you can try rolling back to.
Always try the most recent date available first, and the move backwards until you find a working restore point. , If none of the repair options work, your only remaining option may be to reinstall Windows.
This will erase everything on the hard drive, so it is only recommended as a last-ditch option.
Click here for instructions on reinstalling Windows
7.
Click here for instructions on reinstalling Windows
8.
Click here for instructions on reinstalling Windows Vista. -
Step 2: Click one of the following links based on what happens.
-
Step 3: Check the power cable.
-
Step 4: Remove your laptop's battery and connect the power adapter.
-
Step 5: Try a different monitor.
-
Step 6: Open the computer.
-
Step 7: Check your power supply cables.
-
Step 8: Test your power supply.
-
Step 9: Replace your power supply.
-
Step 10: Check for loose screws.
-
Step 11: Listen to the beep code.
-
Step 12: Try opening your BIOS.
-
Step 13: Check that all of your hardware is detected.
-
Step 14: Open the computer.
-
Step 15: Reseat all of your components.
-
Step 16: Test your RAM modules.
-
Step 17: Try removing your graphics card.
-
Step 18: Remove all unessential hardware.
-
Step 19: Open the Advanced Startup menu (Windows 7 and later).
-
Step 20: Select "Repair Your Computer" or "Launch Startup Repair".
-
Step 21: Log in with your administrator account.
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Step 22: Select "Startup Repair".
-
Step 23: Perform a "System Restore" if Startup Repair fails.
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Step 24: Reinstall Windows.
Detailed Guide
The first step to determine what you'll need to do is to try to turn the computer on. , No response
- Click here if you can't hear any fans starting and can't see anything on the screen, or the computer starts for a moment and then freezes or turns off.
Beep code or POST failure message
- Click here if your computer doesn't pass the POST (Power On Self Test).
This is usually indicated by the lack of a beep and a failure message, or by a series of beeps to indicate an error code.Operating System Not Found or BOOTMGR is missing
- Click here if your computer completes its startup sequence but fails to load Windows. , It may seem simple, but double-check that the power cable is plugged in and the outlet is working.
Plug the computer directly into the wall to see if your surge protector or power strip is the cause of the problem.
If you are using a laptop, make sure that the power adapter is securely connected. , You can run your laptop without a battery inserted as long as you are plugged into a power source.
If your laptop turns on when the battery is removed, something is wrong with the battery and you should contact the manufacturer for a replacement. , If your computer is starting up but you can't see anything, there could be something wrong with your monitor.
Double-check the monitor's connection, and try plugging in a different monitor if possible. , In order to check the connections inside and to test the power supply, you'll need to open the case.
Click here for detailed instructions.
Remember to ground yourself with an antistatic wriststrap or by touching the exposed metal of the case before touching any internal components. , Ensure that the cables that connect your power supply (the box that your power cable is attached to) to your motherboard are securely connected. , Old power supplies have a tendency to fail, but testing them is a relatively straightforward process.
Power supplies are the most common cause for problems with a computer's boot sequence.
Click here for detailed instructions on testing your power supply. , If your power supply doesn't work after testing it, you'll probably need to replace it in order to get your computer working again.
Click here for detailed instructions. , If a screw has come loose in your case, it could be causing your motherboard to short out.
Gently rock your case back and forth and listen for metal rattling.
Either use your fingers or a long pair of tweezers to remove the screw from the case.
Look for any cables that have lost their protective coating, as exposed wiring may be causing a short as well.
Replace any cables that have decayed too much. , If you're "lucky"
your computer will issue a series of beeps when it fails to turn on.
Look up your motherboard's manufacturer and find the beep code translations.
Knowing what the codes mean will make tracking down the problem much easier.Beep codes are unfortunately different for every manufacturer, so you'll need to search for them yourself.
Click here for instructions on identifying your motherboard. , If you can, try entering your BIOS settings menu as soon as your computer starts.
Typical BIOS setup keys include F2, F10, F11, and Del. , Your BIOS will display all of your connected hardware in the MONITOR, HARDWARE, or SYSTEM section.
Check to see that your hard drive is displaying properly.
If your hard drive is not showing up, try replacing the cable inside the computer. , In order to check the various components inside the computer, you'll need to open the case.
Unplug everything from the back and remove the side panel to access the internal components.
Click here for detailed instructions.
Remember to ground yourself with an antistatic wriststrap or by touching the exposed metal of the case before touching any internal components. , Open up your computer and reseat your graphics card, RAM modules, and all of your cable connections.
If anything has come loose, there's a chance that it's disrupting the POST sequence.
You can try reseating your processor as well, but this is usually a much more difficult task, and likely isn't the cause of the problem.
It also increases the chances of damaging the processor, which will render your computer completely inoperable. , There's a chance that a bad memory module is causing your computer to not boot.
Try removing memory modules one at a time and booting your computer to try to isolate a bad memory stick.
You can run a utility like Memtest86 to help determine which of your memory modules is failing. , If you have a dedicated graphics card, try removing it and plugging your monitor into your motherboard's display connection.
A malfunctioning graphics card can cause your computer to not boot.
This article on installing graphics cards will give you detailed instructions on removing your graphics card. , Try booting your computer up with only the most basic hardware attached.
This means disconnecting your graphics card, additional drives, PCI expansion cards, and extra RAM.
After you've removed everything, try turning your computer on.
If your computer works with only the essential hardware installed, add pieces back one at a time, testing each time to see where the problem lies.
If you still cannot pass POST with just your essential hardware, then you'll need to either swap out the essential hardware with spares, take your computer to a repair shop, or upgrade to a new one. , If you are having problems loading Windows, you can try to fix it using Startup Repair.
This is accessible from the Advanced Startup menu if you are using Windows 7 or later.
If you are using Windows Vista or XP, you'll need to boot from the installation disc to access the Startup Repair tools.You can open the Advanced Startup menu by repeatedly pressing F8 as the computer starts up.
If you can't access the Advanced Startup menu, you may have a problem with your hardware.
See the above sections for troubleshooting your boot issues. , You will have to wait a few moments while the necessary files load. , You will be prompted to log in before you can start the repair process. , Windows will scan for problems related to booting the operating system and will attempt to fix them automatically.
Your computer will likely reboot during this process, possibly multiple times.
If Startup Repair fixes something, it is highly recommended to run it at least two more times before trying to boot normally.
Chances are it will fix something else when it runs again., Startup repair may suggest performing a System restore, or you can select it from the main Repair menu.
System Restore will provide several dates that you can try rolling back to.
Always try the most recent date available first, and the move backwards until you find a working restore point. , If none of the repair options work, your only remaining option may be to reinstall Windows.
This will erase everything on the hard drive, so it is only recommended as a last-ditch option.
Click here for instructions on reinstalling Windows
7.
Click here for instructions on reinstalling Windows
8.
Click here for instructions on reinstalling Windows Vista.
About the Author
Justin Anderson
Justin Anderson has dedicated 10 years to mastering lifestyle and practical guides. As a content creator, Justin focuses on providing actionable tips and step-by-step guides.
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