Computers slow down for any number of reasons, but most of those boil down to one thing – us using them. As you download programs, install extensions, surf the web, create files and fill your hard drive with movies and music, inevitably you'll build up virtual detritus that will impact your PC’s performance. So if you've been asking yourself "Why is my computer so slow?", these are the most common reasons your computer is slowing down – and the simple measures you can take to get it running faster.
1. You have too many startup programs
Newly downloaded programs often try to weasel their way into your Startup menu (Windows) or Login Items (Mac). If you didn't uncheck the box for that permission, you could have dozens of unnecessary programs vying to be ready and running as soon as your computer boots up (as if that's happening any time soon).
“The most common cause of a slow computer is too many startup programs,” says Aaron Schoeffler, computer repair doctor at LaptopMD. “90 percent of programs want that permission to start when your computer starts so that you’ll use them, and that can result in a boot time of five to ten minutes. When it finally does start, a ton of programs are already running in the background and if you’re not using a newer computer, that can slow it down.”
While some programs – such as antivirus and firewall software - should be allowed to run from startup, others – such as iTunes or Microsoft Office – could quite easily stay closed until you actually need to access a file from their digital depths.
Mac: Applications / Systems Preferences / User Groups / Login Items, then uncheck unneeded programs. Delete desktop icons you don't use by trashing them or, in the case of files you've saved to your desktop for convenience, reorganizing to the appropriate folder.
Windows 8 and 10: Windows key + X / Task Manager / Startup tab, then right-click on the programs you want to remove and select Disable.
Windows 7 and older: Start button, then search for System Configuration. Go to Startup tab, then uncheck each of the programs if you don't want starting when the system boots up.
2. Your hard drive is failing
“A hard drive nearing the end of its lifespan is a common issue. Hard drives are made of moving parts that spin thousands of times a day and they do wear down,” says Schoeffler “Generally, after two to three years of consistent use, there’s a high chance that a hard drive is failing.”
In contrast, solid-state drives (SSDs) don’t experience the same type of degradation from physical hardware, and have a lifespan of eight to ten years. “Solid state drives are also ten times faster than a standard hard drive, and you’re looking at going from a boot time of three to five minutes to 15-20 seconds,” Schoeffler says. However, SSDs are more expensive per gigabyte of storage – which isn’t a problem if you’re after, say, a 2TB drive, but can get expensive if you need a drive to store large photo or video files.
Run a hard drive check:
Windows 7, Vista: Windows Explorer / Computer / right-click on drive / Properties / Tools / Check Now. You can select “Scan for and attempt recovery of bad sectors” which will prevent your computer from accessing any “bad” areas of the hard drive, but can also increase the scan time to a few hours.
Mac: Head to Applications / Utilities / Disk Utility, then highlight the hard drive in question and click First Aid at the top of the screen.
In general, avoid dropping, throwing or otherwise causing impact to the hard drive to extend its lifespan. At some point, you might consider upgrading your hard drive too: “We tend to recommend upgrading to solid-state drives,” Schoeffler says.
3. Your hard drive is 95% full
When your hard drive gets to 95 percent full, computers can slow down by 50 percent, Schoeffler estimates. “At this point, there is no space to save the temporary files required for operating programs, so it’s as if the OS doesn’t know how to run properly anymore,” he says.
Hard drive space is taken up by programs, updates to programs, and downloads, as well as temporary files and associated files of deleted programs, so you may be able to clear a good amount of space just by emptying your trash. Check your hard drive situation by (Mac) clicking the apple and selecting About this Mac, or (Windows) hitting Start / Computer and right clicking the primary hard drive (usually C:), then go to Properties.
Deep clean your computer of unnecessary files from unused programs to defunct downloads and temporary files. This might include bloatware that manufacturers preload onto computers that are supposed to run utilities or cleanup. System backups and restore points also can take up a huge amount of space, so don’t keep more backup versions than you really need. To optimize space, you might also want to move files to a cloud storage service. Schoeffler recommends the free program CCleaner (Mac/Windows) to easily delete unneeded files, including the glut of temp files created by browsers, for instance.
Wondering about that ancient computer cleaning ritual defragging? That’s only if you’re for some reason still using Windows XP or older – newer Windows PCs and all Macs do not require manual defragging.
4. Your browser has too many add-ons
Browser extensions can usefully enhance your web experience (like an ad-blocker or a unit converter I use) – but they might also be a culprit in slowing down your computer by eating up processing power. Nor are all extensions created equal - some add-ons may proclaim themselves popup blockers or search protectors, but they may be browser adware that can slow your computer down by downloading ads and popping up ads every time you open your browser.
Disable or remove the extensions and toolbars you don't really need:
Firefox: Hit the menu button on the far right, select Add-ons / Extensions, then select disable or remove for each item on the list.
Chrome: Right-click on any extension button / Manage Extensions, then uncheck the box to disable a particular item, or click the trash can to wave it goodbye. You can also check how much memory each extension is using by hitting the top-right menu button (three vertical dots) then More Tools / Task Manager / Memory where you can sort all browser processes by memory used. The extensions will be preceded by a puzzle piece icon.
Safari: Hit Safari (top left) / Preferences / Security / Extensions, then select an item to uninstall. You can also turn off all Extensions here.
Internet Explorer: Tools / Manage add-ons / Show All add-ons, then select the offender(s), and click disable or remove.
Edge: Setting and More / Extensions, then remove any you don't need.
5. You're running too many programs at once
Doing a trillion things at once is exactly why we have computers but, at some point, your little bundle of artificial intelligence is going to falter. Your computer's ability to run multiple programs at the same time hinges in part on its RAM (random access memory), which allows it to switch from processing one program to another with seeming fluidity, but if the demands of the open programs are outstripping your computer's memory and processing power, you'll notice a slowdown.
Head into Task Manager (Windows; Ctrl+Alt+Del) or Activity Monitor (Mac; Cmd+Space, type into Spotlight bar), recommends Schoeffler, to see which programs are open and sucking up processing power:
Then shut down those you don’t need. For Macs, Windows 10, Windows 7 and earlier versions of Windows, you can close the programs from the file menu. In Windows 10 and 8, programs are built so that they run in the background for a while, then automatically shut down. But if you want to manually shut one down and ensure all associated files shut down with it, drag from the top of the screen to the bottom, and hold there until the icon flips over.
6. Too many browser tabs are open
If you're in the dozens of open tabs camp (“All the better to never lose a link”, you claim), your browser is likely hogging far more than its fair share of RAM. “When you open a new browser tab, it’s saved in RAM. If you have only a little bit of RAM left free, you run out of room for processing everything that is active, so the computer slows down,” Schoeffler says
Multiple open browsers can slow down the works, too, and you get extra slow points if any tabs are also auto-refreshing (say, a live blog). What's more, having a glut of browser tabs full of supposedly crucial information doesn't exactly help our efficiency or mindfuless.
Bookmark those “necessary” links (for organization's sake, in a Bookmarks folder titled “To Read”) and shut those tabs down. Even better, One-Tab for Chrome and Firefox does the work for you, compiling all your open tabs into a simple list on a single tab, which can then be accessed as needed.
7. Rogue programs are hogging all the processing powers
It's not always a heavy-duty video or music app that's eating up your computer's processing power. Some programs or system processes may be stuck in a loop or have encountered an error.
Check how much processing power programs and processes are using by heading into Task Manager (Windows) or Activity Monitor (Mac). For both, click the “CPU” tab to order the programs by how much processing power they're taking up. If a program that you're not actively using is still up there in the top few programs, you can select to quit the process.
And, when it comes to browsers, Internet Explorer is especially heavy on your computer, says Joe Silverman, CEO of repair shop New York Computer Help. Most of us aren’t using it anymore– with Chrome and Safari used by the majority of U.S. netizens – but hold up before gleefully uninstalling: “You don't have to run Internet Explorer but don't remove it [if you got it bundled with your Windows PC] – it could cause problems as it's very tied to the operating system,” he says.
8. You have an overzealous antivirus program
Having an active anti-malware program is a vital part of computer hygiene – but yours may be running regular background scans at the worst possible times. “Virus scans slow down the works because they're running in the background,” Silverman says. Some antivirus programs may be set to weekly full scans, which can take a few hours and suck up a lot of processing power.
Head into your antivirus settings and configure it to scan late at night when you aren't using the computer. (However, that feature may not be available on some free antivirus programs – which makes a good case for upgrading.)
9. You have a virus
If it's not the antivirus, it could be the virus. Viruses, spyware and other malware can slow down your computer as they mess around with everything from hijacking your browser to pushing advertising or phishing sites, to crashing your computer. “These days, viruses most commonly install a malicious program that runs ads randomly, which is an easy way to generate income for its creator,” Schoeffler says.
Run a malware scan. Schoeffler recommends using the free Malwarebytes (Mac/Windows) as an anti-malware cybersecurity tool. We also recommended Bitdefender Total Security and Symantec Norton Security Premium.
10. Someone is using your computer for cryptomining
A sluggish computer could signal that a program or ad is using your system to mine cryptocurrency. Often, this occurs because of code on a website and that is active only while the site is open. In fact, some legitimate sites such as Salon use it as a system to generate income instead of users viewing ads (users can opt in if they agree).
“Without your permission, a website could have an extension that uses your computer’s processing power to mine a cryptocurrency,” Schoeffler says. “It’s a legally gray area because it’s not directly doing or adding anything to your system.”
Cryptomining (also called cryptojacking) can also be the result of malware that downloads to your computer – like the Digimine virus that spread through the Chrome version of Facebook Messenger - then runs in the background, mining away and sending information back to its creator.
Shutting down your browser will halt the browser-based cryptomining. To figure out if you’re inadvertently downloaded cryptojacking malware, head to Task Manager (Windows) or Activity Monitor (Mac) and see what’s making demands on your processor. “Whether it’s a virus or browser-based cryptomining, you’ll be able to see if something is using your processor for its own needs,” Schoeffler says.
11. Your OS is way too slick
It's the age-old battle of appearance over performance: Having visual effects enabled – aka eye candy like those snazzy transitions for minimizing windows – can impact the speed of your PC (and to a lesser extent, Mac), if its hardware only just skates within the minimum requirements for your OS of choice.
“If you have a good video card – that's 1GB of RAM on the video card or better – you're OK,” says Silverman. “But less than that, [having visual effects enabled] can slow your computer down.”
Windows 7 and older: Start / Control Panel / Performance Information and Tools / Adjust Visual effects, then click Adjust for best performance or manually choose which effects you'd like to keep.
Windows 8 and 10: Windows key + X / System / Advanced System Settings / Performance Settings / then select as above.
Mac: System Preferences / Dock, then for minimizing applications, change that super-swish Genie effect to a utilitarian Scale effect (basically just disappearing). Uncheck “Animate Opening Applications”.
12. Your room is too dusty
Sometimes the problem is not internal but external – is the back of your CPU casing matted over with dust? This can prevent ventilation which cools the processors as they whir away in an attempt to run Photoshop, Spotify, Outlook, and Skype. And nobody wants a hot computer – heat increases the likelihood of malfunctions and crashes.
As for laptops, any time you notice your laptop heating up, you should check that its vents, usually on the sides, aren't blocked. For example, don't put your laptop on something soft like a pillow where it can sink in.
Dust off the ol', um, dust. If it's really severe, you can use a vacuum cleaner (carefully) or a canister of compressed air.
13. You don't have enough memory
If you've deep-cleaned your computer and modified your browser tab habit, but your computer is still slow (and you own a PC), you might want to consider a minor upgrade in the form of additional RAM.
Some programs take a lot of your computer's RAM to run – for example, programs that work with huge files such as photo or video editing software. “A lot of people try to run Photoshop or some graphics-heavy program on an entry- or mid-level computer that can't handle it,” Silverman says.
If you’re watching videos and playing music, 2GB of RAM should do; and 4GB-8GB if you do graphics-heavy work on your computer. Fortunately, upgrading the RAM on your PC is inexpensive and a task most people can handle themselves. To learn what RAM upgrade options are available for your computer, try Kingston's memory options tool.
14. You need to restart your computer
The reason restarting seems to solve so many tech issues is that programs can get hung for a myriad of reasons. “A lot of stuff gets gummed up in the background. For example, if you turn off Outlook, background processes are still running,” Silverman says. “You could 'end task', but a lot of folks are not that savvy about which one to end.”
Instead of manually digging into Task Manager (Windows) or Activity Monitor (Mac) to divine the root(s) of the sluggishness, restarting flushes out the system, a panacea for those rogue, resource-hogging programs and a clean slate free of files and fragments.
Bite the bullet and shut things down. You even get the added benefit of having critical system updates applied that can only happen during a reboot.
15. You're running in low power mode
Some Windows laptops give you the option to adjust your power settings to maximize performance. Go to Control Panel > Hardware and Sound > Power Options and select "Create a Power Plan." If your computer lets you adjust the speed of your components, you'll see three options: "Balanced," "Power saver," and "High performance." Select "High performance" and create a plan name. You'll then see a screen where you can select your power plan. Select your new plan. Creating a power plan that's based on "High performance" will maximize the performance of your computer automatically.
If you want to tweak the settings further, you can choose "Change advanced power settings" and from the window that opens and you can adjust the settings further.
Updated on 4/3/2019
[Worried woman image via Shutterstock]