Last Updated: May 2026

Is your computer running slow and getting on your nerves? Before spending money on a new PC or upgrades, there are several free fixes worth trying first. In this guide we cover 9 proven ways to speed up a slow computer — all completely free — plus a few bonus tips for when the free options aren’t enough.

These steps work on Windows 10 and Windows 11 unless noted otherwise.

1. Disable Startup Programs

This is the single highest-impact free fix for most slow computers. Every program that launches automatically when Windows starts consumes RAM and CPU before you’ve even opened anything.

In Windows 10 and 11, right-click the taskbar and select Task Manager, then click the Startup tab. You’ll see everything that launches at startup with a “Startup impact” rating. Disable anything rated High or Medium that you don’t need immediately — things like Spotify, Discord, Steam, OneDrive, and manufacturer bloatware are common culprits. You can still launch these manually when you need them.

This alone can cut boot times dramatically and free up RAM for the programs you actually use.

2. Run a Malware Scan

Malware and adware running silently in the background is one of the most common causes of a suddenly slow computer. Windows Defender (built into Windows 10 and 11) has improved significantly and is now genuinely effective for most threats. Open Windows Security from the Start menu and run a full scan.

For a second opinion, Malwarebytes still offers a free version that’s excellent at catching things Windows Defender misses — particularly adware and potentially unwanted programs. Download it, run a scan, remove anything it finds, then uninstall it if you don’t want it running permanently.

3. Free Up Disk Space

Windows needs free disk space to function properly — when your drive gets close to full, performance degrades noticeably. Aim to keep at least 10-15% of your drive free.

The quickest way is Windows’ built-in Disk Cleanup tool. Search for “Disk Cleanup” in the Start menu, select your C: drive, and let it calculate. Check all boxes — Temporary files, Recycle Bin, Thumbnails — and click OK. On a neglected PC this can free up several gigabytes instantly.

For a more thorough cleanup, the free version of CCleaner does a good job finding junk files, browser caches, and leftover temporary files from uninstalled programs.

4. Uninstall Programs You Don’t Use

Unused programs take up disk space and sometimes run background processes even when you’re not using them. Go to Settings → Apps → Installed Apps (Windows 11) or Control Panel → Programs and Features (Windows 10) and sort by size. Uninstall anything you haven’t used in months — old games, trial software, manufacturer utilities you never touch.

Pay particular attention to browser toolbars and extensions, which are notorious for slowing down browsing speed.

5. Adjust Windows Visual Effects

Windows uses significant resources rendering animations, shadows, and transparency effects. On slower PCs turning these off can make a noticeable difference in responsiveness.

Search for “Adjust the appearance and performance of Windows” in the Start menu, click it, and select “Adjust for best performance” — or manually uncheck the effects you don’t care about. The most impactful ones to disable are “Animate windows when minimizing and maximizing” and “Show shadows under windows.”

6. Check for Windows Updates

Pending Windows updates sometimes cause background processes to run constantly, which can throttle performance. Go to Settings → Windows Update and make sure everything is installed and up to date. After updating, restart the PC and check if performance improves.

Also check your drivers — particularly GPU drivers if your PC feels sluggish in graphics-intensive tasks. NVIDIA, AMD, and Intel all offer free driver update tools.

7. Clean Out Dust (Physical Cleaning)

If your PC is more than 2-3 years old and has never been opened, dust buildup is likely causing it to overheat and throttle performance. Modern CPUs and GPUs automatically reduce their speed when temperatures get too high — a process called thermal throttling — which can make a PC feel dramatically slower even though nothing is technically wrong.

Shut down and unplug the PC, open the case, and use a can of compressed air to blow dust out of fans, heatsinks, and vents. For laptops, the intake vents on the bottom and sides are the priority. This is free if you already have compressed air, and the performance improvement can be dramatic on older machines.

8. Defragment Your Hard Drive (HDD Only)

If your PC uses a traditional spinning hard drive (not an SSD), defragmenting it periodically helps performance. Over time files get scattered across the disk, and defragging reorganizes them so the drive can read them faster.

In Windows 10 and 11, search for “Defragment and Optimize Drives” in the Start menu. Select your drive and click Optimize. Windows will tell you if the drive needs it.

Important: Never defragment an SSD. It provides no benefit and causes unnecessary wear. Windows is smart enough to skip defrag on SSDs automatically, but if you’re using a third-party tool make sure it knows the difference.

9. Scan for and Fix System File Corruption

Windows includes a built-in tool called System File Checker that scans for and repairs corrupted system files — which can cause all sorts of performance and stability issues. This is free and takes about 10 minutes.

Open Command Prompt as Administrator (search for cmd, right-click, Run as administrator) and type: sfc /scannow and press Enter. Let it complete. If it finds and repairs files, restart your PC afterwards.

For more serious issues, you can also run DISM: type DISM /Online /Cleanup-Image /RestoreHealth in the same administrator Command Prompt window.

Bonus Tips — When Free Fixes Aren’t Enough

If you’ve tried all of the above and the PC is still sluggish, the issue is likely hardware. Here are the two most cost-effective upgrades:

Add More RAM — If your PC has 4GB or 8GB of RAM and you regularly use a browser with multiple tabs open, editing documents, or gaming, adding RAM is often the single biggest performance improvement you can make. RAM prices are low in 2026 and installing it is straightforward. Use the Crucial Memory Scanner (crucial.com) to find exactly what your PC supports.

Upgrade to an SSD — If you’re still running a traditional spinning hard drive, upgrading to an SSD is transformative. Boot times go from minutes to seconds and everything feels more responsive. A 500GB SSD costs around $40-60 and is the best money you can spend on an older PC.

Frequently Asked Questions

How do I know if my computer has an SSD or HDD?

Search for “Defragment and Optimize Drives” in the Start menu. Next to each drive it will show the media type — “Solid State Drive” or “Hard Disk Drive.”

Will these fixes work on Windows 11?

Yes — all nine tips above work on both Windows 10 and Windows 11. The navigation paths for some settings differ slightly between versions but the features are all present in both.

My computer is still slow after trying everything — what now?

If the PC is more than 6-7 years old and still slow after all these fixes, the hardware itself may be the limiting factor. At that point it’s worth evaluating whether a new budget PC makes more sense than further investment in aging hardware.

Is CCleaner safe to use?

The free version of CCleaner from Piriform is safe and widely used. Avoid the registry cleaning feature — it rarely helps and can occasionally cause problems. Stick to the junk file cleaning functions.