Why Is My Computer So Slow?
By Joe ·
A slow computer is maddening. Pages take forever to load. Programmes freeze. Clicking something and nothing happening. You know the feeling.
The good news is that most slowness has a straightforward cause, and many of the fixes take less than five minutes.
The most common culprits
1. Too many programmes open at once
Every open programme uses memory (RAM). When you run out, the computer starts borrowing space from the hard drive, which is much slower. The result is the computer grinding to a halt.
Fix: Close programmes you’re not using. On Windows, right-click the taskbar > Task Manager to see what’s using the most resources. On Mac, open Activity Monitor (search in Spotlight) and check the CPU and Memory tabs. If something is using an unusual amount, you can force-quit it.
2. The hard drive is nearly full
When a hard drive (or SSD) is over 90% full, it slows down significantly. The computer needs empty space to work in, like needing clear desk space to work efficiently.
Check on Windows: Open File Explorer > This PC and look at the bar under your C: drive. If it’s mostly filled, it’s time to clear space.
Check on Mac: Apple menu > About This Mac > Storage.
Fix: Empty the Recycling Bin / Trash. Delete programmes you no longer use. Move photos and videos to an external drive or cloud storage. The Downloads folder is often full of forgotten large files.
3. Too many programmes starting at login
Every programme that starts automatically when you turn on the computer adds to the startup time, and keeps using resources in the background even when you’re not actively using it.
Fix on Windows: Right-click the taskbar > Task Manager > Startup tab. Disable anything you don’t need to start immediately (music apps, chat apps, cloud sync tools can all be set to open only when needed).
Fix on Mac: System Settings > General > Login Items. Remove anything you don’t need running automatically.
4. Windows Update is running in the background
Windows sometimes downloads and installs updates while you’re trying to work. This can cause dramatic slowdowns, especially on older laptops.
Check: Look for the Windows Update icon in the system tray (bottom right). If it’s active, let it finish and restart the computer, the slowness will likely resolve.
It’s worth letting updates run to completion rather than always delaying them. Security updates are important, and a computer that’s up to date generally runs more smoothly long-term.
5. The computer hasn’t been restarted recently
Computers accumulate temporary files, open connections, and memory leaks over time. A full restart clears all of this and gives the machine a fresh start.
Many people put laptops to sleep rather than shutting down fully. Once a week, do a proper shutdown and start up from cold, not just close the lid.
Windows: Start menu > Power > Shut down (not Restart, Shutdown clears more). Mac: Apple menu > Shut Down.
6. The computer is old
This is the honest answer for some machines. A computer more than seven or eight years old may simply not have enough processing power or memory to run modern software smoothly. Windows 11 and modern browsers are significantly more demanding than they were a few years ago.
Signs this might be the issue:
- The computer was already feeling slow before any of the above applied
- It struggles with video calls even when nothing else is open
- Opening a browser tab takes several seconds
If this sounds familiar, it may be time to talk about whether an upgrade makes sense, and what that would look like for your budget and needs.
Quick wins that take under five minutes
- Restart the computer fully
- Close browser tabs you’re not using (each tab uses memory)
- Plug in the charger, laptops often throttle performance on battery to save power
- Check for Windows Update running in the background
- Empty the Recycling Bin / Trash
When to get help
If you’ve tried the above and the computer is still unreasonably slow, or if it freezes, makes unusual noises, or shows errors, it’s worth getting a second opinion. Sometimes slowness is an early warning sign of a hardware problem (a failing hard drive, for instance) that’s better caught early.
We help with exactly this kind of thing. If your computer has been crawling and you’d like to understand why, get in touch, we can usually get to the bottom of it in a single session.