Last updated: 27 September 2026
Short answer: measure first, then work through the fixes in order: free up disk space, stop unnecessary startup apps, uninstall what you do not use, scan for malware, install updates, check the power mode and trim your browser. Most slow PCs get noticeably faster from those steps alone, at no cost. If you are still on Windows 10, note that security updates for consumers end on 13 October 2026, which matters more than speed.
Why measure before changing anything?
Because "it feels faster" is not a result. Two minutes of measuring tells you where the slowness actually comes from and whether each fix helped.
- Time your start-up. From pressing the power button to a usable desktop, with a phone stopwatch.
- Check what is busy. Press Ctrl + Shift + Esc to open Task Manager, then open the Performance tab. Note CPU, memory and disk use a couple of minutes after start-up, with nothing open.
- Note the pain point. Slow start-up, slow app launches and slow browsing usually have different causes.
If the disk sits near 100 percent for minutes after boot, the drive is the bottleneck. If memory is nearly full with only a browser open, the browser or background apps are.
Which fixes should I do, and in what order?
| Step | Time | What to measure afterwards |
|---|---|---|
| 1. Free up disk space | 10 min | Free space on the system drive |
| 2. Turn off startup apps | 5 min | Start-up time |
| 3. Uninstall unused apps | 10 min | Background processes, free space |
| 4. Scan for malware | 15 to 30 min | CPU use at idle |
| 5. Install updates | Varies | Stability, driver issues |
| 6. Check the power mode | 1 min | Responsiveness |
| 7. Reduce visual effects | 2 min | Responsiveness on very old PCs |
| 8. Trim the browser | 10 min | Memory use |
| 9. Check the drive's health | 5 min | Health status |
| 10. Reset Windows (last resort) | 1 to 2 hours | Everything |
Do them in this order. The early steps are quick, safe and fix the most common causes.
Step 1: Is your drive too full?
Windows slows down when the system drive is nearly full, because it has less room for temporary files and updates. Open Settings → System → Storage to see what is using space, and turn on Storage Sense so Windows cleans temporary files automatically. Cleanup recommendations on the same page finds large files, unused apps and old downloads. As a working rule, leave at least 15 to 20 percent of the drive free.
Step 2: Which startup apps can I turn off?
Many apps set themselves to launch every time Windows starts, and each one adds to start-up time and runs in the background. Open Task Manager → Startup apps (or Settings → Apps → Startup) and look at the Startup impact column.
Turn off anything you do not need the moment you log in: chat apps, update helpers for software you rarely use, game launchers, and manufacturer utilities you never open. Leave security software and anything you recognise as essential, such as your cloud backup. Turning an app off at startup does not uninstall it; you can still open it when you need it.
Step 3: What should I uninstall?
Go to Settings → Apps → Installed apps and sort by size or install date. Remove trial software, old utilities, duplicate tools that do the same job, and preinstalled apps you have never used. Fewer apps means fewer background services and less to update.
Step 4: Could malware be slowing it down?
Yes, and it is worth ruling out. Open Windows Security → Virus & threat protection → Scan options and run a Full scan. If anything suspicious turns up, or the PC behaves strangely, run the Microsoft Defender Offline scan from the same menu, which restarts the PC and scans before Windows loads.
Unknown processes using a lot of CPU in Task Manager while the PC is idle are a warning sign worth checking.
Step 5: Are Windows and the drivers up to date?
Open Settings → Windows Update and install everything available, then look under Advanced options → Optional updates for driver updates. Updated graphics, storage and chipset drivers can fix slowdowns and freezes. Restart afterwards; some updates only finish after a reboot.
Steps 6 and 7: Which settings make a quick difference?
Power mode. On a laptop that is plugged in, open Settings → System → Power & battery and set Power mode to Best performance. The default balanced mode may hold the processor back to save power.
Visual effects. On very old PCs, animations and transparency cost real performance. Press Windows + R, type sysdm.cpl, open Advanced → Performance → Settings and choose Adjust for best performance, then tick back Smooth edges of screen fonts so text stays readable.
Step 8: Is the browser the real problem?
Often, yes. A browser with dozens of tabs and many extensions can use more memory than everything else combined. Remove extensions you do not use, close tabs you do not need, and turn on your browser's memory-saving or sleeping-tabs feature. Check Task Manager again afterwards: the memory figure usually drops noticeably.
Step 9: Is the drive failing, or just slow?
Open PowerShell and run:
Get-PhysicalDisk | Select-Object FriendlyName, MediaType, HealthStatus
A HealthStatus other than Healthy means back up now; the drive may be failing. If MediaType shows HDD, a spinning hard drive is almost certainly your biggest bottleneck. That is the one case where a small purchase, a solid-state drive, transforms an old PC more than any setting. It is not free, but it is often the best value upgrade there is.
Step 10: When should I reset Windows?
If the steps above have not helped, a reset gives you a clean system. Open Settings → System → Recovery → Reset this PC and choose Keep my files. It removes installed apps and settings but keeps your documents.
Back up first, every time. My 30-minute backup setup covers how to do it properly.
What should I avoid?
- Registry cleaners and "PC optimiser" apps. They rarely help and can break things.
- "RAM booster" tools. Windows manages memory itself; forcing memory free usually slows things down.
- Turning off Windows Update or security software. Any speed gain is not worth the risk.
What if I am still on Windows 10?
Windows 10 support ended on 14 October 2025. Microsoft's Extended Security Updates programme keeps consumer PCs on version 22H2 receiving security fixes until 13 October 2026, and after that date an unenrolled consumer PC gets no more security updates at all.
Check whether your PC can run Windows 11 with Microsoft's PC Health Check app. If it can, upgrading is free. If it cannot, the PC may still be fine for offline tasks, but using it for banking, email and client work without security updates is a real risk. If replacement is on the horizon, I covered what to look for in how to pick a laptop for engineering work in 2026. And if the PC is fine but the internet still feels slow, work through why your Wi-Fi is slow before blaming the computer.
FAQ
Will more RAM speed up my PC?
Only if you regularly run out of it. If Task Manager shows memory nearly full during normal use, more RAM helps. If memory use is moderate, extra RAM makes little difference, and the steps above matter more.
Is it worth replacing a hard drive with an SSD?
On an old PC with a spinning hard drive, usually yes. It is the single upgrade that makes the biggest difference to start-up and app launch times. It costs money, so it sits outside this free guide, but it is worth knowing.
How often should I do this maintenance?
A quick check every few months is enough: review startup apps, clear space and install updates. Storage Sense and automatic updates handle much of it for you.
Does resetting Windows delete my files?
Not if you choose Keep my files, which keeps your personal documents but removes apps and settings. Always back up before a reset anyway, in case something goes wrong.
