The whole computer crawls
Why has my laptop become so slow all of a sudden?
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
Slowness almost always comes from too many programs starting with the computer, a nearly full drive, or an old spinning hard disk struggling to keep up. The quickest thing to try first: see what is eating the machine — Open Task Manager with Control, Shift and Escape, click the CPU column to sort, and look at the top few rows. On a Mac use Activity Monitor. Whatever sits above fifty percent is your culprit. Most people are done in about 25 minutes.
Full walkthrough below: 6 steps for Windows and Mac, rated easy.
Sounds like this
- •Apps take ages to open
- •Typing lags behind
- •Fan runs constantly
Why it happens
Slowness almost always comes from too many programs starting with the computer, a nearly full drive, or an old spinning hard disk struggling to keep up.
Work through these in order
0% done- 1
See what is eating the machine
Open Task Manager with Control, Shift and Escape, click the CPU column to sort, and look at the top few rows. On a Mac use Activity Monitor. Whatever sits above fifty percent is your culprit.
- 2
Stop programs starting with the computer
In Task Manager open the Startup apps tab and disable everything you do not need instantly, such as chat apps, update helpers and cloud drives. Leave your antivirus alone.
- 3
Free real space on the drive
Open Settings, System, Storage, and clear temporary files and the recycle bin. Aim to keep at least fifteen percent of the drive empty, because a full drive slows everything down.
- 4
Cut down browser tabs and extensions
Each tab uses memory. Remove extensions you never chose deliberately, since toolbars and coupon add-ons are a classic cause of a slow browser.
- 5
Restart properly once a week
Choose Restart rather than Shut down. On Windows, Shut down does not fully clear memory because of fast startup, but Restart does.
- 6
Consider a solid state drive
If the computer still has an old spinning hard disk, swapping it for a solid state drive is the single biggest speed improvement you can buy, and it costs less than a new laptop.
If none of that worked
If one process named Antimalware Service Executable stays high, let a full scan finish once. It calms down afterwards.
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Who wrote this and how we checked it
The CommonFixes team
Writer and researcher
We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.
- Everyday repairs
- Windows and Mac
- Plain language
CommonFixes review desk
Technical editor
Before a guide goes live, a second person walks through it on a real machine and checks each instruction against the maker's own support pages. Anything we cannot confirm is removed rather than guessed at.
- Fact checking
- Safety warnings
- Source links
This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
A gentle reminder: back up anything you cannot afford to lose before major repairs. If a step ever feels risky, stop and ask a technician. There is no shame in that.