What to do right now when your computer stops responding

When your computer freezes, your first move is to wait 30 seconds. Many freezes resolve on their own—a program is using all your processor power, or your hard drive is catching up. If nothing changes after half a minute, force-close the frozen program instead of restarting the whole machine.

On Windows, press Ctrl + Alt + Delete, then click Task Manager. Look for any program marked "Not Responding" in the list. Click it once to select it, then click the End Task button at the bottom right. The program will close, and your computer should become responsive again.

On Mac, press Command + Option + Escape to open the Force Quit window. Select the frozen program and click Force Quit. Your computer will close that program and return to normal.

If the entire screen is frozen and you cannot move the mouse or keyboard, or if Task Manager itself will not open, then restart your computer. Hold the power button for 10 seconds until the machine shuts down completely, wait 30 seconds, then turn it back on. You may lose unsaved work in open programs, but a restart is the only way out of a complete system freeze.

Key Takeaways

  • Wait 30 seconds before taking action, because many freezes clear on their own.
  • Use Task Manager on Windows or Force Quit on Mac to close a frozen program without restarting.
  • A full restart is necessary only when the entire screen is frozen and you cannot open Task Manager.
  • Freezes usually come from one program using too much memory or processor power, or from a hard drive that is too full.
  • Keeping your operating system and programs updated, and leaving at least 10 percent of your hard drive empty, prevents most freezes.

Why your computer freezes in the first place

A freeze happens when your computer runs out of resources to do what you are asking it to do. The most common cause is memory overload—you have too many programs open, or one program is using far more memory than it should. Your computer's RAM (the fast, temporary memory it uses while running) fills up, and the system slows to a crawl or stops responding entirely.

The second major cause is a hard drive that is too full. Your computer needs empty space on the drive to write temporary files and to move data around while programs run. When your drive is more than 90 percent full, freezes become common. Check how much space you have left by opening File Explorer (Windows) or Finder (Mac) and looking at your main drive.

A third cause is outdated drivers or operating system software. Drivers are the small programs that let your operating system talk to your hardware—your graphics card, network adapter, and so on. When a driver is old, it can cause conflicts that freeze the system. The same is true for your operating system itself; Microsoft and Apple release updates that fix freezing bugs.

Malware and viruses can also cause freezes, though this is less common on modern computers with built-in security. If your computer freezes frequently and you have not restarted in weeks, or if you have downloaded files from untrusted sources, malware is worth ruling out.

How to check what program is using too much memory

Task Manager (Windows) and Activity Monitor (Mac) show you exactly which programs are consuming the most resources. Open Task Manager on Windows with Ctrl + Alt + Delete, then click the Processes tab. Look at the Memory column—programs are listed from highest to lowest memory use. If one program is using 50 percent or more of your total RAM, that is likely your culprit.

On Mac, open Activity Monitor by pressing Command + Space, typing "Activity Monitor", and pressing Enter. Click the Memory tab. Again, look for any program using a large percentage of your total memory. The "% Memory" column shows the percentage of your total RAM each program is using.

If you see a program you recognize using excessive memory—say, your web browser with 20 tabs open—close some tabs or restart the program. If you see a program you do not recognize, search for its name online before closing it; some system processes have unfamiliar names and should not be closed.

Freeing up hard drive space

If your hard drive is more than 90 percent full, your computer will freeze regularly until you delete files or move them to external storage. Start by emptying your Recycle Bin (Windows) or Trash (Mac)—files you delete do not actually leave your drive until you empty these folders.

Next, look for large files you no longer need. On Windows, open File Explorer, right-click your main drive, and select Properties. Click Disk Cleanup to see a list of temporary files, old Windows updates, and other items you can safely delete. On Mac, open Finder, click About This Mac in the top menu, then click Storage to see what is taking up space.

Video files, photo libraries, and old backups take up the most space. If you have large folders you do not use regularly, move them to an external hard drive or cloud storage like Google Drive or OneDrive. This frees up space on your main drive without losing the files.

As a general rule, keep at least 10 percent of your hard drive empty. If your drive is 500 GB, aim to use no more than 450 GB.

Updating your operating system and drivers

Microsoft and Apple release updates regularly that fix bugs, including freezing issues. On Windows, open Settings, click Update & Security, then click Check for updates. If updates are available, install them and restart your computer. On Mac, open System Preferences, click Software Update, and install any available updates.

Drivers are trickier because they vary by hardware. If you have a graphics card made by NVIDIA or AMD, visit their website and read the latest driver for your card model. If you have a printer, scanner, or other external device, check the manufacturer's website for driver updates. Most drivers update automatically on modern Windows and Mac systems, but checking manually can help if you are experiencing frequent freezes.

After updating, restart your computer. Updates often require a restart to take effect, and a restart also clears your RAM, which can resolve freezing on its own.

When to call a professional

If your computer still freezes after you have closed programs, freed up hard drive space, and updated your operating system, the problem may be hardware-related. A failing hard drive, overheating processor, or faulty RAM can cause freezes that software fixes cannot solve. A computer repair technician can run diagnostics to check your hardware.

You should also call a professional if you suspect malware. If your computer freezes even when no programs are running, or if you see unfamiliar programs in Task Manager or Activity Monitor, a technician can scan for viruses and remove them safely.

If your computer is under warranty, contact the manufacturer's support line before paying for a repair. Many manufacturers offer free support for hardware issues during the warranty period.

Preventing freezes going forward

The easiest way to prevent freezes is to restart your computer once a week. A restart clears your RAM, closes background programs you may have forgotten about, and gives your operating system a chance to clean up temporary files. Many freezes straightforward do not happen on computers that restart regularly.

Keep your browser under control. Web browsers use a lot of memory, especially with many tabs open. Close tabs you are not using, or use a tab manager extension that suspends inactive tabs. If you use multiple browsers, pick one and stick with it—running Chrome, Firefox, and Edge at the same time will freeze most computers.

Install updates as soon as they are available, rather than postponing them. Updates fix security holes and bugs, including freezing issues. Set your computer to install updates automatically so you do not have to think about it.

Frequently Asked Questions

Is it bad to force-quit a program?

Force-quitting a program is safe and will not damage your computer. You will lose any unsaved work in that program, but everything else stays intact. It is far better than restarting your whole computer.

Will restarting my computer delete my files?

No. A restart shuts down your computer and turns it back on. All your files stay on your hard drive. You will lose any work you have not saved in open programs, so save your work before restarting if you can.

How much RAM do I need to avoid freezes?

Most modern computers come with 8 GB of RAM, which is enough for everyday use. If you regularly work with video editing, large spreadsheets, or many browser tabs, 16 GB is better. You can check how much RAM you have in Task Manager (Windows) or Activity Monitor (Mac).

Can a full hard drive cause freezes even if I have plenty of RAM?

Yes. Your computer needs empty space to write temporary files while programs run. A drive that is more than 90 percent full will cause freezes regardless of how much RAM you have. Deleting files or moving them to external storage usually fixes the problem.

What is the difference between a freeze and a crash?

A freeze means your computer stops responding but is still running—you can force-quit programs or restart. A crash means a program closes suddenly without warning. Crashes are usually caused by bugs in the program itself, while freezes are usually caused by resource overload.