Here’s Why Your Computer’s So Slow — Plus, How To Fix It

Whether you use your laptop as a glorified Netflix machine or you’re running a side hustle out of Notion, most computer users are all-too-familiar with the spinning wheel of doom. On Macs, it’s that rainbow swirly cursor that eventually gives way to “Application Not Responding” on the regular. If you’re a PC user, you might be arch nemeses with the retro hourglass cursor or the blue circle. But even before that icon pops up, you probably know that your computer is running slowly.

The age-old question “Why is my computer so slow?” is one that many assume is left up to the whim of the computer gods. But, before you pronounce your laptop dead on arrival, there’s still hope for your computer and its processing speed — so long as you know what to look for.

“In the past, it used to be common that computers would slow down because the components inside them would become slower over time,” explains Carmen Zlateff, partner director of program management at Microsoft Windows. “Today, computers slow down mostly because we install more and more apps on them, without ever removing anything. [...] All that activity is what is taking computer power away from what you’re trying to use the computer for.”

With the right tools, troubleshooting techniques, and tips from industry experts, you can revive your computer and get back to high-speed surfing.

We at Bustle only include products that have been independently selected by our editors. We may receive a portion of sales if you purchase a product through a link in this article.

The Experts

Carmen Zlateff leads the Windows User Experience team. Having worked at Microsoft for over 25 years, Zlateff has held roles across product management, software development, and overseeing various core UX operations.

Veronica Esbona is the president of InGear Public Relations, a communications agency specializing in consumer technology. Esbona is the head of PR for Women in Consumer Technology, an organization that works to connect and empower women in the consumer technology industry.

Why Is My Computer So Slow?

From malware to storage or the general age of a device, there are myriad reasons as to why your computer is slow. When assessing this issue, you’ll first want to run a few diagnostic tests.

Storage

Esbona recommends checking on your device’s storage first. “As a hard drive nears its capacity, its processing speed slows down, sometimes by as much as 50%,” explains Esbona. “The simple answer is that there’s not much virtual memory left that’s needed to save the temporary files that are necessary to run programs.”

Check the free space on your PC’s hard drive by clicking on “My Computer,” then right-clicking on “Local Disk C” and seeing the properties of your computer. On a Mac, click on the Apple in the top-left corner of your screen, select “About This Mac,” then navigate to Storage. If your total disk space isn’t at least 20% free, Esbona says it’s time to do some spring cleaning on your computer’s memory.

Too Many Programs

Another key reason for a computer lagging, according to Zlateff, is having too many applications running. “If your computer is running slow, start by closing all the app and browser windows you aren’t currently using,” says Zlateff. “You might be surprised by how much that speeds things up.” Zlateff also recommends checking which apps are programmed to run when your computer is powered on, and which are programmed to run in the background.

On Mac, you can check this by heading to the Activity Monitor under Finder > Applications > Utilities > Activity Monitor. Here, you’ll see a full list of applications and processes currently running, and can quit them accordingly. On PC, press Ctrl + Shift + Esc to open Task Manager, then head to Processes > Apps to see which apps are running. Close the ones you don’t need.

Outdated Software

Of course, as with any tech bug, another common reason for decreased computer speed is the software not being up to date. To see if your computer is in need of a software update, head to your Settings on your PC or System Preferences on your Mac. On PC, click “Update and Security,” then “Check for updates.” On your Mac, click “Software Update” from the Settings menu, and the window will automatically check if you’re due for an update.

Viruses Or Malware

One of the more nefarious reasons your computer might be lagging is due to malware. “Users are sometimes tricked to install these from Internet links after looking for apps which will speed up or clean up their computer,” says Zlateff. Both Esbona and Zlateff recommend running an antivirus scan to assess whether the reason for your computer’s lagging is due to an unwelcome visitor.

How Do I Clear Space On My Computer?

If, after assessing your computer’s disk space, you find that low storage is the likely cause of your slow computer, it’s time to summon your inner Marie Kondo. Some quick steps that Esbona recommends for an overloaded disk are emptying your trash bin and running a disk cleanup utility on Windows or on your Mac to remove unnecessary or temporary files. If you’re using Windows, Zlateff recommends using the Storage Sense feature to manage your drive space.

Alternative Storage Options

While you might be getting trigger-happy command-clicking on loads of unnecessary files, there are always files you can’t part with. If that work presentation is dragging down your computer speed, or that family vacation photo album is overstaying its welcomed in your disk space, Esbona and Zlateff recommend some alternative storage options.

One of the easiest ways to clear storage off of your computer is through the Cloud. If you’re using an Apple device, you can purchase an iCloud storage subscription to store files safely. For PC users, Zlateff recommends Microsoft OneDrive. Some other services that work for most devices are DropBox and Google Drive. Not only does using a cloud service save space, but Zlateff emphasizes that it also “makes them easily accessible from your phone and ensures those files won’t be lost if something happens to your computer.”

Feel a bit skeptical about storing all of your precious files in the vague, almighty cloud? You can always opt for something more physical. Esbona recommends an external drive, which you can purchase at most tech stores and upload your files to.

How Do I Get Rid Of Malware On My Computer?

If you suspect your laptop’s lag might be a symptom of an underlying bug, it’s time to go on the defense — and offense — against potential viruses. “If your computer is not that old and you’ve already removed any unnecessary apps and made sure there’s free space on the hard drive,” Zlateff explains, “it’s possible your computer may have been infected with malware.”

When assessing potential viruses or malware, Zlateff emphasizes that it’s important to ensure you’re running a solution you can trust. “Don’t install any apps from Internet links unless you have great confidence that the company you’re downloading that app from is trustworthy.”

For Windows users, Zlateff recommends Microsoft Defender, a built-in antivirus program in Windows 10 and 11. Apple’s iOS also regularly provides security updates. So, to keep your defenses strong, Zlateff recommends turning on automatic security updates.

As for antivirus solutions outside of your computer’s software security, a few reputable antivirus programs include Norton AntiVirus and McAfee.

If All Else Fails…

If you’re a PC owner, one of the last methods you might be able to bank on is the PC’s ability to be upgraded. If you have an older PC, Zlateff says that adding more RAM or a solid state drive to your computer might sufficiently boost its performance. (If this sounds like a foreign language to you, it might be best to leave this upgrade to a service like Geek Squad.)

However, if you’ve tried all of the above methods (along with the old turn-off-and-on fallback) and you’re still not seeing an improvement in your speed, your computer may just be unfortunately dying of natural causes. Both Esbona and Zlateff say that there might not be any quick fixes for a device that’s five years or older with processing issues.

“It may be time to consider investing in a new, modern computer,” says Zlateff. “Considering how much of our lives are online these days — work, school, social, play — it's an investment likely to pay off in boosted productivity and time saved.”