A slow computer is one of the most common tech frustrations, and the good news is that most slowdowns have a cause you can fix for free. The trick is to work in order, from the quick and costless to the paid, so you do not spend money before you need to. Below are the steps for both Windows and Mac, with an honest note at the end about when a computer is simply past its best.

A quick word of reassurance: before assuming your machine is worn out, know that cluttered startup lists, full drives, and background apps account for a huge share of slowness, and none of those cost a penny to fix. Whether you are on a PC or a Mac, the same principles apply — the differences between Mac and PC matter less here than you might think.

Restart the computer first

It sounds too simple, but a restart fixes more slowdowns than almost anything else, especially if you are someone who just closes the lid instead of shutting down.

  1. Save any open work.
  2. On Windows, click Start > Power > Restart (choose Restart, not just Shut down, as it does a cleaner reset on many systems).
  3. On a Mac, click the Apple menu > Restart.
  4. Let it fully boot back up before judging the speed.

A restart clears out memory, closes background tasks that got stuck, and installs updates that were waiting. If your computer has been on for days or weeks, this step alone may be all you need.

This matters more than it used to. Most people now close the laptop lid or put the machine to sleep rather than shutting it down, so it can go for weeks without a true restart. Over that time small memory leaks and stuck processes pile up quietly until everything feels sluggish. Making a habit of a full restart once or twice a week heads off a surprising amount of slowness before it ever starts.

Cut down apps that launch at startup

If your machine is slow from the moment it turns on, too many programs loading at startup is the usual culprit. This is the highest-impact free fix.

  1. On Windows, press Ctrl+Shift+Esc to open Task Manager, click the Startup apps tab, and look at the “Startup impact” column.
  2. Select any app you do not need the instant you log in, and click Disable. Chat apps, update helpers, and device utilities are safe to disable; leave security software on.
  3. On a Mac, go to System Settings > General > Login Items & Extensions.
  4. Select items under “Open at Login” that you do not need and click the minus (–) button to remove them from startup.

Disabling a startup app does not uninstall it — you can still open it whenever you want, it just will not load automatically and slow your boot.

Free up disk space

A drive that is almost full drags down the entire system, because it needs spare room for temporary files and virtual memory. Aim to keep at least 10 to 15 percent free.

  1. On Windows, open Settings > System > Storage and turn on Storage Sense, or run the built-in Disk Cleanup tool to clear temporary and system files.
  2. Empty the Recycle Bin (Windows) or Trash (Mac), which can quietly hold gigabytes.
  3. On a Mac, open System Settings > General > Storage, then use the recommendations and “review files” options to clear large items.
  4. Move big folders of photos and videos to an external drive or cloud storage to reclaim space for good.

If you are constantly running out of room, that is itself a sign the drive is too small for how you use the machine, which points toward the upgrade section later.

Uninstall programs you do not use

Years of installed software, trials, and bundled “bloatware” take up space and sometimes run in the background.

  1. On Windows, go to Settings > Apps > Installed apps, scroll the list, and click the three dots then Uninstall for anything you do not recognise or use.
  2. On a Mac, open the Applications folder in Finder and drag unwanted apps to the Trash, or use the app’s own uninstaller if it has one.
  3. Be cautious: if you are unsure what something is, leave it, especially anything from the computer’s maker or labelled as a driver.

Removing a few large programs you never open frees space and cuts background activity in one move.

Scan for malware

A machine that became slow seemingly overnight, runs hot, or shows odd pop-ups may be infected. Malware is a very common and overlooked cause.

  1. On Windows, open Windows Security (search for it in the Start menu), go to Virus & threat protection, and run a full scan.
  2. On a Mac, built-in protections handle most threats, but if you suspect something, run a scan with a reputable security app you trust.
  3. Remove or quarantine anything flagged, then restart.
  4. Avoid downloading “PC cleaner” tools from pop-up ads — many are the very problem they claim to fix.

While you are thinking about what runs in the background, it is also worth checking what is quietly eating resources right now. On Windows, the Task Manager’s Processes tab shows which apps are using the most CPU, memory, and disk; on a Mac, Activity Monitor does the same. If one program is pinned near the top and you are not actively using it, closing it — or uninstalling it if it keeps coming back — can restore responsiveness immediately.

Update your operating system

Updates are not just for features; they include performance and security fixes that can resolve slowdowns.

  1. On Windows, go to Settings > Windows Update and install anything pending, then restart.
  2. On a Mac, open System Settings > General > Software Update and install available updates.
  3. While you are there, update your web browser and main apps too.
  4. Set updates to install automatically so you do not fall behind again.

Tame your browser tabs and extensions

For many people, the “slow computer” is really a slow browser. Each open tab and extension uses memory, and it adds up fast.

  1. Close tabs you are not actively using — if you want to keep them, bookmark them first.
  2. Open your browser’s extensions page and remove any add-ons you do not recognise or use.
  3. Restart the browser after clearing it out.
  4. If one website is the problem, check whether it is a heavy page rather than your whole computer.

If your machine slows to a crawl only with lots of tabs open, that is a classic sign you are short on memory — more on that next.

One more free check that people skip: heat. A laptop whose vents are clogged with dust, or that sits on a soft surface like a bed or sofa, can overheat and deliberately slow itself down to cool off — a process called thermal throttling. If your computer runs hot and loud and then feels sluggish, give the vents a careful clean and use it on a hard, flat surface. It is a genuine, cost-free fix that often gets overlooked.

Consider hardware upgrades (honestly)

If the free steps have not done enough, the issue may be the hardware itself, and here it pays to be honest about cost and limits.

  1. The biggest single boost is swapping a mechanical hard drive for an SSD, which can cut boot and load times dramatically. Our guide on SSD versus HDD explains why.
  2. The next best is more memory. If you run many apps or tabs and the system constantly swaps to disk, adding RAM helps — our explainer on what RAM is covers how much you need.
  3. Check first whether your computer can be upgraded. Many modern laptops have the storage and memory soldered in and cannot be changed.
  4. Weigh the cost. If a machine is old and needs several upgrades, that money may be better put toward a new computer.

And the honest bottom line: some slowdowns are simply age. A computer many years old, with a processor from a different era, has a ceiling that no setting or cleanup can lift. If you have worked through everything here and it is still painful to use, you have not failed — you have reached the point where replacing it is the sensible choice rather than more tinkering.