What to do when your computer is running slow

"My computer is so slow" is probably the number one reason people call me. And nine times out of ten, the fix is simpler and cheaper than they expect. You don't always need a new machine — sometimes you just need to clear the cobwebs.

Here's exactly what I check, in order, when someone tells me their computer has slowed to a crawl.

Restart it (seriously)

I know. It sounds patronising. But you'd be surprised how many "slow" computers haven't been properly restarted in weeks. Sleep mode and closing the lid don't count — that's like taking a nap versus getting a full night's sleep.

A proper restart clears out temporary files, resets memory, and closes background processes that have been quietly piling up. Right-click the Start button (Windows) or click the Apple menu (Mac), choose Restart, and let it fully come back up. If your computer has been "on" for a fortnight, this alone might fix it.

Check what's running in the background

Your computer might be slow because something is secretly using all its resources. On Windows, press Ctrl+Shift+Esc to open Task Manager and click "More details." On Mac, open Activity Monitor from Applications > Utilities.

Sort by CPU or Memory usage and look for anything eating a huge percentage. Common culprits:

• Browser tabs. Each open tab uses memory. If you've got 47 tabs open "for later," your computer is trying to keep all of them alive at once. Bookmark them and close them.
• Cloud sync services. OneDrive, Google Drive, and Dropbox can hammer your system when they're syncing large folders.
• Software updaters. Adobe, Java, and various apps love to run background update checkers that consume resources.
• Antivirus scans. If your antivirus is running a full scan, your computer will be sluggish until it finishes.

Check your storage

When your hard drive gets too full, everything slows down. Your computer needs free space to think — as a rough guide, keep at least 15-20% of your drive free.

On Windows: Open Settings > System > Storage. On Mac: Click the Apple menu > About This Mac > Storage.

If you're nearly full, the quick wins are:

• Empty the recycle bin / trash
• Clear your Downloads folder (it's probably full of installers you ran once two years ago)
• Use the built-in cleanup tools — Storage Sense on Windows or "Manage" on Mac
• Move photos and videos to an external drive or cloud storage

Check for malware

Sometimes a slow computer is a sick computer. Malware, adware, and unwanted browser extensions can chew through your resources while doing things you really don't want happening.

Run a scan with Malwarebytes — the free version is fine for a one-off check. It catches things that standard antivirus often misses, particularly adware and browser hijackers.

While you're at it, check your browser extensions. Open your browser's extensions page and remove anything you don't recognise or no longer use.

Install updates

I know — I keep banging on about updates. But an outdated operating system genuinely runs slower. Updates include performance improvements, not just security patches. Let Windows Update or macOS Software Update run to completion, restart, and see if things improve.

The hardware question

If you've done all of the above and it's still slow, it might genuinely be a hardware limitation. Two upgrades make the biggest difference:

• Adding an SSD. If your computer still has a traditional spinning hard drive, replacing it with a solid-state drive is the single biggest speed improvement you can make. It's like going from a bicycle to a car. Everything opens faster — booting, loading apps, opening files.
• Adding RAM. If your computer has 4GB of RAM and you're running a modern browser with a few tabs, you're probably maxing it out. Bumping to 8GB or 16GB gives your system room to breathe.

Both upgrades are usually cheaper than a new computer and can add years of life to an older machine.

When it really is time for a new one

If your computer is 8+ years old, can't run the latest operating system, and the hardware can't be upgraded — it might genuinely be time. That's okay. A decent laptop for everyday use doesn't have to cost a fortune, and I'm always happy to help you pick one that fits what you actually need (not what the salesperson wants to sell you).

If your computer is driving you mad and you've tried the basics, give me a shout. I can usually diagnose the problem in a single visit and give you honest advice about whether it's worth fixing or time to move on.