How to Speed Up a Slow Windows 11 PC

Your PC was fine a year ago. Now it takes forever to boot, everything feels sluggish, and you're wondering if it's time for a new one. Before you spend any money, try these fixes. Most of them are free and take a few minutes each.

I've been fixing PCs in St Helens since 2008, and nine times out of ten, a "slow computer" doesn't need replacing. It just needs sorting out.

1. Disable Startup Programs

This is the single most common cause of a slow PC. Over time, programs add themselves to your startup list, and every one of them loads when you turn your computer on, fighting for resources before you've even opened anything.

Press Ctrl+Shift+Esc to open Task Manager, then click the Startup apps tab. You'll probably see a long list. Anything you don't need running immediately when you log in can be disabled. Right-click it and choose Disable.

Common culprits that don't need to be there:

• Spotify: it'll open when you want it, doesn't need to be waiting in the background
• Microsoft Teams, unless you're using it for work every day
• Adobe Creative Cloud: just opens when you launch an Adobe app anyway
• Manufacturer bloatware. HP, Dell, and Lenovo all love adding "helper" apps that do nothing useful
• Printer software. HP especially installs a whole suite. You don't need it. Windows handles printing fine on its own

2. Uninstall Software You Don't Use

Go to Settings → Apps → Installed apps and sort by size. You'll probably find programs you forgot you had, trials that expired years ago, and pre-installed bloatware from the manufacturer.

Uninstall anything you don't recognise or don't use. If you're not sure about something, leave it. Things like old printer software, browser toolbars, free antivirus trials, and "PC cleaner" tools can safely go.

3. Turn Off Visual Effects

Windows 11 has animations, transparency, shadows, and smooth scrolling everywhere. It looks nice, but on older hardware it's burning resources on eye candy instead of running your apps.

Open the Start menu and search for "performance", then click Adjust the appearance and performance of Windows. You'll see this dialog:

Select "Adjust for best performance" to turn everything off, then tick "Smooth edges of screen fonts" back on. Without that, text looks awful. Click OK and the difference is immediate, especially on older machines.

4. Check for Malware

Some malware is designed to be invisible while it chews through your CPU. Crypto miners are a common one. Your PC feels slow but you can't see why.

Open Windows Security (search for it in the Start menu), go to Virus & threat protection, and run a Full scan, not just a Quick scan. A full scan checks every file on your system and takes a while, but it's thorough.

5. Free Up Disk Space

When your main drive is nearly full, Windows struggles. It needs free space for virtual memory, temp files, updates, and general breathing room. If your C: drive is above 90% full, that's a problem.

Go to Settings → System → Storage and click Temporary files. Tick everything you're comfortable removing and delete it.

But the real gains come from the classic Disk Cleanup tool run as administrator.

6. Run Disk Cleanup as Administrator

This is the step most people miss. The normal Disk Cleanup tool only shows your user files. Running it as administrator unlocks system-level cleanup (old Windows updates, previous installations, delivery optimisation files). This can reclaim gigabytes.

1. Open the Start menu and search for Disk Cleanup
2. Select your C: drive and click OK
3. When it opens, click "Clean up system files"
4. Select your C: drive again and wait for it to scan
5. Tick the big items (see below)

That "Previous Windows installation(s)" entry is the Windows.old folder, left behind after major Windows updates. It can easily be 20GB+ and serves no purpose once you're happy with the update.

7. Turn Off System Restore

This one surprises people, but System Restore can genuinely slow your PC down. It hooks into file system operations to track every change, creating restore points in the background. On a machine that's already struggling, that overhead adds up, and the restore points themselves eat disk space, which makes the problem worse.

The thing is, System Restore is a leftover from the XP and Windows 7 era when it was your only real recovery option. Windows 10 and 11 have much better alternatives built in:

• Reset this PC, which reinstalls Windows while keeping your files
• Windows Recovery Environment (startup repair, rollback updates, command prompt access)
• In-place upgrade repair, which reinstalls Windows over the top without losing anything
• Driver rollback, built into Device Manager if a driver update causes problems

To turn it off, search for "Create a restore point" in the Start menu, select your C: drive, and click Configure:

Select "Disable system protection" and click OK. Then click Delete to remove existing restore points and reclaim the space. You won't miss it. Your real safety net is a proper backup of your files, not restore points.

8. Check for Windows Updates

A pending Windows update can cause slowness, especially if it's been trying to install in the background for weeks. Go to Settings → Windows Update and let it finish whatever it's doing. Restart when it asks.

Occasionally a bad update causes problems too. If your PC got noticeably slower after an update, go to Windows Update → Update history → Uninstall updates and remove the most recent one to see if that helps.

9. Upgrade Your Hardware

If you've tried everything above and it's still slow, the bottleneck is probably hardware. Two upgrades make the biggest difference:

Replace the hard drive with an SSD

This is the single biggest upgrade you can make to any PC. If your computer takes more than 30 seconds to get to the desktop, it almost certainly has a traditional spinning hard drive. Swapping it for an SSD (solid state drive) makes everything dramatically faster: boot time, opening programs, file transfers, everything.

An SSD upgrade is straightforward, and your data can be migrated across so you don't lose anything. It's the upgrade I recommend most often because the difference is night and day.

Add more RAM

If your PC grinds to a halt when you've got a few browser tabs open and a couple of programs running, you might not have enough RAM. Open Task Manager (Ctrl+Shift+Esc), click the Performance tab, and check Memory. If it's consistently above 80–90%, more RAM would help.

8GB used to be plenty, but with modern Windows and the way browsers eat memory, 16GB is the sweet spot for most people now.

When It's Actually Time for a New PC

Sometimes the honest answer is that the machine has had its day. If it's 8+ years old, has a low-end processor, and you've already maxed out the RAM and put an SSD in, there's only so much you can do. But that's genuinely rare. Most "slow" PCs just need some of the steps above.

If you'd rather hand it over and have someone work through all of this for you, I do computer repair and tune-ups in St Helens and can usually have it back to you running like new within a day.

Mark

Mark has been fixing computers since the late '90s and went self-employed in 2008. Based in St Helens since 2013, he works evenings and weekends from his home in Laffak — friendly, affordable repairs for PCs, laptops, and Macs. See reviews on Google