Why is My Computer So Slow All of a Sudden? Here's How to Speed Things Up Again

If your computer is slow all of a sudden, you might be facing some kind of isolated glitch. You don't have to worry too much about it, as simply restarting your computer can get rid of it. However, the problem can be due to something more serious too, like a virus running amok. You'll have to scan your PC with your anti-virus and see what it says.

My computer has randomly gotten slow a couple of times. The first time it happened, I rebooted my PC, because I had a feeling I was dealing with something minor. This pretty much took care of the slowness, but the second time around, it wouldn't go away. Turns out, one of my drivers was outdated.

If you'd like to know how I fixed this, and all the other reasons the issue can pop up, you can read ahead.

Why is My Computer So Slow All of a Sudden?

There are a few different reasons why your computer can be slow all of a sudden.

Let's take a look at them.

1. Minor Glitches

The first reason why you might be dealing with a slow computer could be a minor software glitch. It's hard to say how or why it popped up, but you should be able to clear it by simply restarting your computer.

Here's how you can restart your Windows computer:

• Click on the Windows start button
• Click on the Power button
• Select the Restart option
• Wait for your slow computer to reboot, and then check whether it is still running slow

Here's how you can restart your Mac computer:

• Head to the Apple Menu
• Click on the Restart option
• Wait for your Mac computer to reboot, and then check whether it is still running slow

2. Background Programs Accessing System Files

Your computer might be slow because of background programs eating your system's resources. They may either be starting on their own when your computer boots, or are programs that you've opened and forgotten to close.

Here's how you can check whether your startup programs are eating your resources on Windows:

• Click on the Search bar
• Search for Task Manager
• Open Task Manager from the drop-down list
• Click on the Processes tab - you should open resource monitor now
• From the performance monitor window, go through the app list and find all the apps/background processes that you have open right now, and check how much CPU and memory they take up, and then compare it with the other apps
• If you feel like it takes up too much resources, you should consider disabling it

Here's what you do on Macs:

• Press the Command and Space keys to open your Mac Spotlight
• Search for Activity Monitor
• Click on Activity Monitor from the search results
• Go through the CPU and Memory tabs to check all your apps, and how many resources they use
• Once you've checked the performance monitor, decide whether the processes/apps you have running now need to be disabled or not

If you've figured that these background apps are wasting too many resources, you can right-click them from the taskbar, and then select End Task to close them if they're currently running. But if they're apps that automatically open the moment your PC launches, you can stop them from doing this. Here's how:

• Open Settings
• Click on Apps
• Select Startup Programs
• Toggle off all the apps that you want to disable from automatically starting

Here's how you stop apps from automatically launching on Macs:

• Launch the app that automatically starts
• Right-click on its icon on the dock
• Untick the Open at Login option
• Confirm the change

3. Low Storage Space (Low Disk Space)

A lot of the time, the issue can be due to low disk space. You probably have been downloading files, and have filled up your drive. You not only would face your computer processing power being slow, but it might also be turning on and off randomly.

Now, there's a way to check how much storage space you've used. Here's what you can do on Windows computers:

• Click on the Windows Start button
• Select Settings
• Go to System
• Select Storage from the left-hand panel
• Select This PC
• Go to the Storage Usage section
• Check the free space that's available

Here's what you do on Macs:

• Click on your Apple menu
• Select System
• Click on General from the sidebar (you may need to scroll down a bit)
• Click on Storage from the right side
• Select the All Volumes option
• Open Storage Settings
• Go through your computer's available storage space now

On both Mac and Windows computers, there's a special optimization feature that lets you see all the files that you can do without.

Here's how you can use it and improve computer performance on Windows:

• Click on the Windows Start button
• Go to Settings
• Go to System
• Select Storage
• Choose Cleanup Recommendations
• Go through the file list, such as the 'Large and Unusued File' downloads folder section
• You should see a list of recommended unnecessary files to clear for disk cleanup
• Select the ones you would want to delete, and then select the Cleanup button (remember that these files will be permanently deleted so double-check whether you will need them)

Here's what you do on Mac:

• Click on the Apple menu in the left corner of the screen
• Select the About This Mac option from the dropdown menu
• Click on the Storage tab from the window that appears
• Choose the Manage button
• Wait for the Storage Management window to launch
• You should see a couple of different ways to optimize your storage now, like the Optimize Storage option. Once enabled, it automatically deletes any TV shows or movies that you've downloaded into your iTunes library, and can identify large files that you don't use anymore and recommend deleting them

4. Outdated Operating System

Your operating system being outdated can be the cause of the slow performance. If you're dealing with an outdated OS, you probably already know. Update prompts would've been popping up.

Here's how you can do a Windows update:

• Select the Start button
• Choose Settings
• Click on the Windows Update button
• Select the Check for Updates option
• If there is a firmware version that you can download, it should pop up
• Click on it and then wait for your computer operating system to upgrade
• Check if your computer running slow still

Here's how you can update Mac computers:

• Click on the Apple menu
• Click on the System's Settings button
• Click General from the sidebar (you may need to scroll down to find it)
• Select the Software Update button
• If there is a firmware version that you can download, it should appear on the screen
• Select it and then wait for your Mac computer operating system to upgrade
• Check if your computer running slow still

To make sure you never face operating system problems again, you can go ahead and enable automatic updates. Your computer will automatically download the latest firmware whenever it's available now.

Here's how you can switch it on Windows computers:

• Click on the Start button
• Select the Settings button
• Click on Update & Security from the menu
• Choose the Windows Update option from the left-hand side
• Click on the Advanced Options button
• You should see a window called 'Choose How Updated are Installed'. Click on it
• Select 'Automatic' from the drop-down menu
• Check the Give Me Updates for Other Microsoft Products option too

Here's what you do on Mac computers:

• Click the Apple Menu
• Select the System Settings
• Click General from the sidebar
• Click Software Update from the right-hand side
• Click on the Automatic Updates option
• Select Done to finish up and confirm

5. Corrupt Operating System (Broken Operating Systems)

Apart from all of the above, you may be dealing with a slow PC, possibly because your OS is corrupt.

You can figure this out easily, actually - there are a lot of tell-tell signs. For instance, you'd get hit with the Blue Screen of Death regularly, have programs constantly crashing, and have applications that won't launch

This issue isn't really something that you face on Macs. So, here's how you can fix it on Windows computers:

• Click on Start
• Enter Command prompt into the Windows search bar
• Launch the Command Prompt with your Administrator permissions
• Type in the following command in: DISM /Online /Cleanup-Image /RestoreHealth
• Wait for the DISM tool to find system issues, which should pinpoint why you have a slow Windows computer
• Activate your Windows System File Checker by typing Sfc/Scannow
• Wait for it to scan your system
• It will try to fix whatever is causing you to have a slow Windows computer. Follow the prompts that pop up that let it do this

6. Virus Running Loose

Your PC's processing power can slow down if you're dealing with a virus running loose. Whatever is on your computer would be sucking up its resources to keep itself going. Now, there are a few different ways that you can take care of this. You can either use your computer's security system, or whatever anti-virus you have installed.

Here's how you can use the built-in security tool on Windows:

• Click on the Windows Start button
• Open Settings
• Choose the Update & Security option
• Select Windows Security from the left-hand side panel
• Navigate to the Virus & Threat Protection section
• Click on the Quick Scan button
• Wait for the Windows Security feature to scan your system
• If you feel like the Quick Scan was not enough, you can go with Full Scan instead. You will once again have to wait for the Windows Security Feature to scan your PC
• Review your scan results - it should pop up on the screen. There should be prompts if a virus, or anything malicious was detected
• Check your PC's performance now

Here's how you use the built-in Mac security feature:

• Click on the Apple menu that is in the top left-hand corner
• Select System Preferences from the drop-down menu
• Choose Security & Privacy
• Click on General from the Security & Privacy tab
• Ensure the Automatically Update Safe Downloads List button is enabled
• Wait for your OS to check for any viruses now -

Here's how you can use an anti-virus, like Avast:

• Launch the Avast App (can be accessed from your System tray)
• Navigiate to the Avast scan menu
• Go through the different scan options and pick the one that you want to perform. It can either be a Quick Scan, Full System scan, or a Custom scan. The custom scan lets you check any specific files and folders to see if they're infected
• Select the desired scan type
• Click on the Start button to initiate the process
• Wait for the Avast tool to finish examining your system
• You should see the results from the scan pop up afterwards. There should also be prompts on how you can take care of the problem

7. Overheating Computers

There's a chance that your computer is acting up because it's overheating. This could be due to a few different reasons, like your CPU fans being clogged with dust.

If your PC is overheating, its components are probably working overtime to keep it cool. So, your system is slowing down, as a result. It does take a bit of work to clean your CPU fans, but I've broken it down as easy for you.

Here's what you can do on a PC:

• Switch your computer off
• Proceed to open your PC case back panel
• Look for your CPU fan (you may need to use your manual to find it)
• Use a screwdriver to remove your CPU fan from the motherboard's circuit
• Dust off any dust and grime
• Use a compressed air can on your fan's blades
• Re-attach the CPU fan to its slots, and make sure it's slotted into place properly
• Turn your computer back on and then check whether you're still dealing with a slow computer

Here's what you can do on a Mac computer:

• Shut down your Mac
• Remove your computer's bottom cover using a screwdriver
• Locate the CPU fan - should be located towards the top of your device (you can use your Mac's manual to find it)
• Use a compressed air can on the fan's blades
• Re-assemble your Mac, and then turn it back on again and check if you're still stuck with the slow performance issue

8. Faulty or Missing Drivers

Your computer's performance can also be affected if you have outdated drivers. Now on Mac computers, your system drivers automatically update the moment you update your operating system. So, you don't have to worry about doing anything extra here.

But on Windows computers, you'll have to manually get the job done. There actually are 2 ways that you can do this - you can either use a third-party tool, like the Avast Updater, or go through with the process manually.

Here's method 1:

• Go to the Avast tool website
• Download it, and then run it
• Click on the Scan Drivers button
• Click on the Download button next to the outdated graphics driver that pops up

Here's method 2:

• Open the search bar from your PC taskbar
• Search for Device Manager
• Click on the Device Manager option when it pops up
• Click on the Category button
• Right-click your graphics card driver
• Tap the Search Automatically for Updated Driver option
• Click on the Update Driver button, and wait for the latest firmware to install

9. Hardware Issues

Last but not least, you might be having a slow computer on your hands because of hardware issues, like your RAM or hard drive being broken. There's really nothing you can do about this, other than open your PC up, inspect it, and then replace them.

Depending on when you bought your computer/ the hardware parts, you might be able to get them fixed for free (if you still have their warranty). Definitely call the shop you got them from and inform them about what you're facing.

FAQ

Answered below are some popular questions.

1. How Can I Make Windows 11 Run Faster?

I would recommend that you make sure that your OS is updated - you'll be running the latest Windows versions, so you won't have to worry about any potential bugs ever slowing you down.

Apart from this, I would recommend updating your RAM and swapping your Hard drive for a Solid State Drive. By upgrading your RAM, you would have programs open faster, as the upgraded RAM would mean more memory. However, upgrading RAM can be a bit of work - you can check this other guide I've written for an easy breakdown.

When it comes to going with a solid-state drive instead of a hard drive, you'd be able to retrieve data from it quicker, which would also help with speed.

Lastly, I'd suggest that you clean your computer regularly. Its insides may be dusty, so your CPU fan may not be able to do a good job of cooling your PC. The process to follow can be a bit tough, but I broke it down for you earlier.

2. What Do You Do If Your Internet Connection is Slow?

Generally speaking, if your internet was fine and it's suddenly slow, your internet service provider/network administrator might be responsible. They may be going through some kind of network tower issue, so you'll have to wait it out for them to take care of things.

But also, your router might be glitching out. So, the best possible fix would be to turn it off and then back on again.

Read more resources

Final Thoughts

If you are dealing with a slow computer, you may be facing it because of a random glitch. So, try and restart your desktop and see whether this helps. But if it doesn't do the trick, the issue can be due to background programs eating up too many resources, existing files being corrupted, or even a virus.

Overall, the issue can be quite easy to fix, and a lot of the reasons for the problem are the same on both Windows and Mac computers. Hopefully, you found everything discussed useful, and are able to improve your computer performance now.