Why Is My Computer Not Working?

Your computer may not be working due to power issues, such as a faulty power supply, dead battery, or loose cables. If it turns on but doesn’t boot, the problem could be a hardware failure (RAM, hard drive, or motherboard) or a corrupted operating system. Malware infections, outdated drivers, or recent software changes can also cause crashes and slow performance.

A computer that won’t turn on or function properly can be frustrating, especially when you need it for work, school, or entertainment. There are many reasons why this might happen, ranging from simple power issues to serious hardware failures.

In this guide, you’ll learn about the most common reasons your computer might not be working and how to fix them. Whether your PC won’t turn on at all, gets stuck while booting, or crashes randomly, you’ll find troubleshooting steps to help get it running again.

The first thing to check is power-related issues—if your computer isn’t turning on, it could be due to a faulty power connection or a drained battery. Let’s start with that.

Power Issues: Computer Won’t Turn On

If your computer doesn’t turn on at all—no lights, no fans, no sounds—the problem is likely related to power. Here are some common causes and how to fix them.

1. Check the Power Source and Cables

• Make sure your computer is plugged into a working power outlet. Try plugging in another device to test the outlet.
• Inspect the power cable for any damage or loose connections. If possible, use a different cable to see if that fixes the issue.
• If you’re using a power strip or surge protector, try plugging the computer directly into the wall.

2. Test the Battery (Laptops Only)

• If you’re using a laptop, the battery might be completely drained or faulty.
• Plug in the charger and wait a few minutes before trying to turn it on.
• If the laptop only works when plugged in, the battery might need to be replaced.

3. Check the Power Button

• Press and hold the power button for at least 10 seconds to force a restart.
• If the button feels stuck or unresponsive, it could be broken. A repair technician may need to fix it.

4. Look for Signs of Life

• Do you hear fans spinning or see lights blinking? If not, the power supply might be dead.
• If your PC turns on but immediately shuts off, the power supply unit (PSU) could be failing.

5. Try a Different Power Supply (Desktops Only)

• If none of the above steps work, the PSU might be the problem. If you have access to another compatible power supply, swap it out and test.
• If you’re not comfortable working inside your computer, take it to a professional for diagnosis.

Startup Failures: Computer Turns On but Doesn’t Boot

If your computer turns on but doesn’t load the operating system, there could be a hardware or software issue preventing it from starting properly. You might see a blank screen, a loading loop, or an error message. Here’s how to troubleshoot.

Check for Beeping Sounds or Error Codes

When a computer has trouble starting, it sometimes gives clues through beeping sounds or error messages. If you hear a series of beeps, your motherboard is trying to tell you what’s wrong. The pattern of beeps can indicate issues with RAM, the processor, or other hardware components. Check your computer’s manual or manufacturer’s website to decode these signals.

If an error message appears on the screen, write it down or take a picture. Searching for the exact message online can help you find a solution specific to your problem.

Test the Monitor and Display Connections

Sometimes, the computer is actually running, but the screen isn’t displaying anything. Check that the monitor is properly connected and turned on. If you’re using an external display, try unplugging and reconnecting the cable. Switching to a different monitor or using another display port can help determine if the issue is with the screen or the computer itself.

If you’re using a laptop, shine a flashlight at the screen. If you see a faint image, the backlight may be broken, and you’ll need professional repair.

Disconnect External Devices

USB devices, external hard drives, and other peripherals can sometimes interfere with startup. Unplug everything except the keyboard and mouse, then restart your computer. If it boots up normally, one of the disconnected devices may be causing the problem.

Try Booting Into Safe Mode

Safe Mode is a special way to start your computer with only the most essential programs running. If your computer starts but gets stuck loading Windows or macOS, try booting into Safe Mode.

For Windows:

1. Turn off your computer and turn it back on.
2. As soon as it starts, repeatedly press F8 (on older PCs) or hold Shift + F8 while booting.
3. If that doesn’t work, try turning the computer on and off a few times until you see Advanced Startup Options.
4. Select Safe Mode and see if the system loads.

For macOS:

1. Turn off your Mac and press the power button.
2. Immediately hold Shift until you see the Apple logo.
3. Release the key and wait for Safe Mode to load.

If your computer starts in Safe Mode, the issue is likely a faulty driver, recent update, or malware infection.

Run Startup Repair or System Diagnostics

Windows and macOS both have built-in tools to fix startup problems. If your computer repeatedly fails to boot, try using these recovery options.

• Windows: Use Startup Repair by booting into Advanced Startup Options (hold Shift while restarting).
• Mac: Use Disk Utility in macOS Recovery (press Command + R at startup).

These tools can automatically detect and fix certain startup issues, such as missing or corrupt system files.

Operating System Not Loading

If your computer turns on but gets stuck on the startup screen, shows a blue screen (Windows), or displays a spinning wheel (Mac), the operating system may be corrupted or facing software conflicts. Here’s how to troubleshoot.

Boot Into Safe Mode

Safe Mode loads only the necessary files needed for the system to run, making it a useful tool for diagnosing software problems. If you didn’t try this in the previous step, follow these steps:

• Windows: Restart and hold Shift + F8 or boot into Advanced Startup Options (hold Shift while clicking Restart). Select Safe Mode from the menu.
• Mac: Restart and hold Shift until you see the Apple logo, then release it.

If your computer starts in Safe Mode, uninstall any recent software updates or drivers that may have caused the issue.

Run Startup Repair (Windows) or Disk Utility (Mac)

Windows and macOS both have built-in repair tools to fix startup problems.

• Windows:
  
  1. Restart the computer and enter Advanced Startup Options (Shift + Restart).
  2. Select Troubleshoot > Advanced Options > Startup Repair.
  3. Follow the on-screen instructions to fix issues.
• Mac:
  
  1. Restart and hold Command + R until the Apple logo appears.
  2. Select Disk Utility and choose your startup disk.
  3. Click First Aid to scan and repair disk errors.

If these tools detect and fix an issue, restart your computer to see if it loads properly.

Check for Corrupt System Files (Windows Only)

Windows has a built-in tool to scan for and repair corrupted files.

1. Open Command Prompt (in Advanced Startup Options, select Command Prompt).
2. Type sfc /scannow and press Enter.
3. Wait for the scan to complete, then restart your PC.

If it finds and fixes errors, your computer should boot normally again.

Try System Restore

If your computer was working fine a few days ago but suddenly won’t start, a System Restore might help. This feature rolls your system back to a previous working state without deleting personal files.

• Windows:
  
  1. Go to Advanced Startup Options > Troubleshoot > Advanced Options > System Restore.
  2. Choose a restore point from when your computer was working normally.
  3. Follow the instructions to restore your system.
• Mac:
  
  1. Boot into macOS Recovery (Command + R at startup).
  2. Select Reinstall macOS (this keeps your files intact).

If System Restore works, it means a recent update or software change caused the issue. If not, you may need to reinstall your operating system.

Hardware Failures That Prevent Functionality

If your computer turns on but still doesn’t work properly, faulty hardware might be the cause. Problems with RAM, storage, or overheating can prevent your system from functioning correctly. Here’s how to check for and fix common hardware failures.

Check and Reseat the RAM

Faulty or improperly installed RAM can prevent your computer from booting or cause random crashes. If your PC beeps when turning on or shows a black screen, RAM might be the issue.

1. Turn off your computer and unplug it from power.
2. Open the case (for desktops) or remove the back panel (for some laptops).
3. Locate the RAM sticks and gently remove them.
4. Reinsert them firmly into their slots.
5. Close the case, reconnect power, and try turning the computer on.

If your computer still doesn’t work, try using only one RAM stick at a time to identify a faulty module.

Test the Hard Drive or SSD

A failing hard drive or SSD can prevent your operating system from loading. If you hear clicking noises from your hard drive or your computer frequently freezes, your storage device might be failing.

• For Windows: Boot into Advanced Startup Options > Command Prompt and type:
  • chkdsk /f /r to scan and fix drive errors.
• For Mac: Boot into macOS Recovery > Disk Utility > First Aid to check for disk issues.

If your computer can’t detect the drive, you might need to replace it.

Check for Overheating Issues

Overheating can cause a computer to shut down or fail to boot. Dust buildup in fans and vents can lead to poor airflow, making the system overheat.

• Look for warning messages about overheating during startup.
• If the computer feels hot, let it cool down before turning it on again.
• Clean out dust using compressed air, especially around cooling fans.
• Make sure all fans (CPU, GPU, and power supply) are spinning properly.

If your CPU or GPU is overheating even after cleaning, reapplying thermal paste or upgrading cooling solutions might be necessary.

Inspect the Motherboard and Power Supply (Desktops Only)

If your desktop turns on but shows no display or repeatedly shuts down, a failing power supply or motherboard could be to blame.

• Try a different power supply unit (PSU) if possible.
• Look for physical damage like burnt areas or swollen capacitors on the motherboard.
• If the motherboard is faulty, professional repair or replacement is needed.

Software or Malware-Related Problems

If your computer turns on but runs slowly, crashes frequently, or behaves strangely, software issues or malware infections could be the cause. Corrupt system files, faulty drivers, or malicious programs can prevent your computer from working properly. Here’s how to fix them.

Scan for Malware and Viruses

Malware can slow down your computer, cause crashes, or block access to files and programs. If you suspect a virus, follow these steps:

1. Boot into Safe Mode (Shift + Restart on Windows, Shift key on Mac).
2. Open your antivirus program and run a full system scan.
3. Remove any detected threats and restart your computer.
4. If you can’t access your antivirus, use Windows Defender Offline or a bootable antivirus USB.

If malware is deeply embedded, a full system reset may be necessary.

Undo Recent Changes

If your computer started having issues after installing a new program, driver, or update, it could be causing the problem.

• Uninstall Problematic Software:
  
  • Windows: Open Control Panel > Programs > Uninstall a program and remove recently installed apps.
  • Mac: Drag the app to the Trash and clear system cache files.
• Roll Back Drivers:
  
  • Windows: Open Device Manager, right-click the problematic driver, and select Rollback Driver.
  • If rollback isn’t available, try updating or reinstalling the driver.

If undoing changes fixes the issue, avoid reinstalling the same software or driver version.

Check for Corrupt System Files

If Windows files are damaged, your system might crash, freeze, or fail to boot. Use these built-in tools to check for corruption:

1. Run System File Checker (Windows):
   

Open Command Prompt (Admin) and type:
sfc /scannow

• Press Enter and wait for the scan to complete. Restart your computer.

2. Use Disk Utility (Mac):
   
   • Boot into macOS Recovery (Command + R), open Disk Utility, and run First Aid.

If errors are found, follow on-screen instructions to repair them.

Perform a System Restore

If none of the above solutions work, restoring your computer to a previous state can fix software-related problems without deleting personal files.

• Windows:
  
  1. Go to Advanced Startup Options > System Restore.
  2. Select a restore point before the issues started and follow the instructions.
• Mac:
  
  1. Boot into macOS Recovery (Command + R).
  2. Select Reinstall macOS (this keeps your files but reinstalls the OS).

When to Seek Professional Help

If you’ve tried all the troubleshooting steps and your computer still isn’t working, it may be time to get professional assistance. Some problems require advanced tools or hardware replacements that are difficult to fix at home. Here’s when you should consider taking your computer to a technician.

Signs You Need Expert Help

1. No Power or Repeated Shutdowns – If your computer won’t turn on at all or shuts down randomly, a failing motherboard, power supply, or CPU may be the cause. These components require specialized testing and replacement.
2. Frequent Blue Screens or Errors – If your computer crashes regularly, even after reinstalling the operating system, there could be a deeper hardware issue like a failing hard drive or bad memory.
3. Overheating Even After Cleaning – If your computer keeps overheating despite cleaning the fans and vents, the cooling system or thermal paste might need professional servicing.
4. Strange Noises or Burning Smells – Clicking sounds from the hard drive, coil whine from the power supply, or a burnt smell from the motherboard are signs of serious hardware failure. Stop using the computer immediately to prevent further damage.
5. Data Recovery Needed – If your computer won’t boot and you need to recover important files, data recovery specialists can help retrieve lost information from a failing hard drive or SSD.

Where to Get Help

• Manufacturer Support – If your computer is under warranty, contact the manufacturer for repairs or replacements.
• Local Repair Shops – A certified technician can diagnose and fix hardware or software issues.
• Authorized Service Centers – Apple, Dell, HP, and other brands have official service locations for major repairs.