Start with the basics before you panic

Most PC problems have straightforward causes: a loose cable, a full hard drive, too many programs running at once, or Windows needing a restart. Before you assume something is broken, check the power connection, make sure your monitor is plugged in and switched on, and restart your computer. If your PC is running slowly, close programs you are not using and check how much free space is left on your drive.

If the problem persists after a restart, the next step depends on what is actually happening. Is your PC not turning on at all? Is it turning on but not showing anything on screen? Is it running but freezing or crashing? Is it making unusual noises? Each symptom points to a different cause and a different fix.

Key Takeaways

  • Always restart your PC first and check that all cables are plugged in firmly, because most problems go away after a restart.
  • If your PC will not turn on, check the power outlet with another device, and make sure the power button is actually being pressed.
  • If it turns on but shows nothing on screen, try a different monitor cable or a different monitor before assuming the PC itself is broken.
  • Slow performance usually means your hard drive is full, too many programs are running at startup, or your hard drive is failing.
  • If your PC is making clicking or grinding noises, stop using it and back up your files when ready, because the hard drive may be failing.

PC will not turn on at all

First, confirm the power outlet itself is working. Plug a lamp or phone charger into the same outlet. If that device does not work, the outlet is dead—try a different outlet or call an electrician. If the outlet works, the problem is with your PC or its power cable.

Next, press the power button and listen. You should hear the fan start and see lights on the case or keyboard. If you hear nothing and see no lights, the power cable may be loose. Unplug the power cable from the back of the PC, wait five seconds, and plug it back in firmly. Press the power button again. If the PC still does not respond, try a different power cable if you have one available—the cable itself may be damaged.

If the PC turns on (you hear the fan and see lights) but nothing appears on the monitor, move to the next section. If it still will not turn on after trying a different outlet and cable, the power supply inside the PC may have failed, and you will need to take it to a repair shop.

PC turns on but monitor shows nothing

The monitor cable may be loose or plugged into the wrong port. Look at the back of your PC. You will see one or more video ports—they are usually blue, black, or white rectangular or round connectors. Unplug the monitor cable from the PC, wait a few seconds, and plug it back in firmly. Make sure it is pushed all the way in until you hear or feel a click.

If that does not work, try plugging the monitor cable into a different video port on the back of the PC. Some PCs have more than one. If your PC has both an integrated graphics port (usually closer to the center of the back panel) and a dedicated graphics card port (usually lower), try both.

If you still see nothing, try a different monitor or a different monitor cable. Borrow one from a friend or from another PC if you can. If a different monitor works, your original monitor or cable is faulty. If a different monitor also shows nothing, the graphics card or motherboard inside your PC may have failed, and you will need professional repair.

PC is running slowly or freezing

Open File Explorer and right-click on your C: drive (or whichever drive Windows is installed on). Select Properties. Look at the pie chart—if the blue section (used space) takes up more than 80 percent of the circle, your drive is too full. Windows needs free space to work properly. Delete files you no longer need, move large files to an external drive, or uninstall programs you do not use.

Next, check what programs are running at startup. Press Ctrl + Shift + Esc to open Task Manager. Click the Startup tab. You will see a list of programs that launch when Windows starts. Disable any you do not need by right-clicking and selecting Disable. Programs like Spotify, Discord, Slack, and cloud storage services often start automatically and slow down your PC.

If your PC is still slow after freeing up space and disabling startup programs, your hard drive may be failing. Listen for clicking or grinding noises coming from inside the case. If you hear those sounds, stop using the PC and back up your files when ready—the drive could fail completely at any time. Take the PC to a repair shop or replace the hard drive yourself if you are comfortable opening the case.

PC crashes, restarts on its own, or shows a blue screen

A blue screen with white text (called a Blue Screen of Death or BSOD) usually means Windows encountered an error it could not recover from. Write down any error code shown on the screen—it often appears as something like "DRIVER_IRQL_NOT_LESS_OR_EQUAL" or a code like 0x0000007E. Restart your PC and search for that error code online to find the specific cause.

If your PC restarts without showing an error, the problem is often overheating. Feel the air coming out of the back of the case—if it is very hot, the cooling fan may be clogged with dust. Shut down the PC, unplug it, and use a can of compressed air to blow dust out of the vents and fan. Do this outside or in a well-ventilated area, because a lot of dust will come out.

If crashes continue after cleaning the fan, a hardware component may be failing. Run Windows Update to make sure your drivers are current. Press Windows key + I to open Settings, click Update & Security, and click Check for updates. Install any updates offered and restart. If crashes still happen, take the PC to a repair shop—the problem may be a failing hard drive, bad RAM, or a failing power supply.

PC makes clicking, grinding, or beeping noises

Clicking or grinding sounds coming from inside the case usually mean the hard drive is failing. Stop using the PC when ready and back up your important files to an external drive or cloud storage. Do not wait—a failing drive can stop working completely without warning, and you may lose everything on it.

Beeping sounds during startup are usually a sign of a hardware problem. One beep is normal. Repeated beeping (like one long beep followed by two short beeps) indicates a specific hardware failure. Look up the beep pattern online along with your PC manufacturer's name—different manufacturers use different beep codes. Most beep codes point to failing RAM or a graphics card that is not seated properly. If you are not comfortable opening the case, take the PC to a repair shop.

When to take your PC to a repair shop

You can safely try restarting, checking cables, freeing up disk space, and disabling startup programs on your own. These steps fix most problems and do not risk damaging anything. Stop and seek professional help if any of the following are true: your PC makes clicking or grinding noises, you see a blue screen with an error code you cannot find information about, the PC overheats even after you clean the fan, or the problem involves opening the case to reseat or replace hardware.

A local computer repair shop can diagnose the problem in 30 minutes to an hour, usually for a small fee. They can tell you whether the fix is straightforward (a loose cable, a driver update) or expensive (a new hard drive, a new power supply). If you are not sure whether you should open the case yourself, it is safer and faster to let a professional do it.

Frequently Asked Questions

Is it safe to restart my PC if it is frozen?

Yes. If your PC is completely frozen and will not respond to mouse or keyboard input, hold down the power button for 10 seconds until the PC shuts down completely. Wait 30 seconds, then press the power button to turn it back on. This is a hard shutdown and is safe to do, though it is better to restart normally when possible.

What does it mean if my PC is running hot?

Your PC generates heat, and the cooling fan removes it. If the case feels very hot to the touch or the fan is running constantly at high speed, dust may be blocking the vents. Shut down the PC, unplug it, and use compressed air to blow dust out of the vents and fan. If it is still hot after cleaning, the fan itself may be failing and needs to be replaced.

Can I fix a PC with a virus myself?

If you suspect a virus, read and run Windows Defender (built into Windows) or a free tool like Malwarebytes. Both can scan your PC and remove most common viruses. If your PC is so slow or frozen that you cannot read anything, restart in Safe Mode by holding Shift while clicking Restart, then read and run a scan from Safe Mode.

What should I do before taking my PC to a repair shop?

Back up any important files to an external drive or cloud storage first. The repair shop may need to erase the drive or replace it, and you do not want to lose your files. Write down exactly what the PC is doing wrong—when it started, what error messages you saw, and what you have already tried.

How often should I restart my PC?

Restart at least once a week, or whenever you notice it running slowly. Restarting clears temporary files from memory, closes programs that may be using resources, and installs Windows updates that require a restart. Many PC problems go away after a restart, so it should always be your first troubleshooting step.