Start with the easiest fixes: disk cleanup and startup programs

Windows 10 slows down mostly because your hard drive is full, programs are running in the background when you don't need them, and temporary files pile up over time. You can recover speed without buying new hardware by removing what you don't use and telling Windows to stop launching programs automatically.

The fastest single fix is to disable startup programs. When you turn on your computer, Windows launches dozens of applications in the background—some you installed, some that came with Windows. Each one takes memory and processing power. You can see which programs start automatically and turn off the ones you don't need every single day.

Open Task Manager by pressing Ctrl + Shift + Esc. Click the Startup tab. You'll see a list of programs with a "Status" column showing "Enabled" or "Disabled". Right-click any program you don't need running all the time—Spotify, Discord, Dropbox, Adobe updates—and select Disable. Restart your computer. You'll notice it boots faster when ready.

Key Takeaways

  • Disable startup programs in Task Manager to free up memory and speed up boot time without uninstalling anything.
  • Run Disk Cleanup and Storage Sense to remove temporary files, old Windows installations, and cached data that Windows no longer needs.
  • Uninstall programs you haven't used in months through Settings > Apps, which frees both disk space and background processes.
  • Check your hard drive's free space—Windows runs noticeably slower when the drive is more than 85% full, even if you have plenty of RAM.
  • Disable visual effects like animations and transparency if your computer is older, which can make the interface feel snappier on slower hardware.

Use Disk Cleanup and Storage Sense to remove temporary files

Windows stores temporary files while you work—browser cache, old Windows updates, installation files, and crash logs. These accumulate and take up gigabytes of space. Disk Cleanup and Storage Sense are built into Windows 10 and remove these files safely.

Open Settings by pressing Windows key + I. Go to System, then Storage. You'll see a breakdown of what's using space on your drive. Click Temporary files at the bottom. Windows will show you what it can delete: Recycle Bin contents, temporary files, old Windows installations, and cached data. Check all the boxes and click Remove files. This usually frees 1 to 5 gigabytes depending on how long it's been since you cleaned up.

You can also turn on automatic cleanup. In the same Storage settings, scroll down and toggle Storage Sense to On. Set it to delete temporary files automatically every 30 days. This prevents buildup without you having to remember to clean manually.

Uninstall programs you no longer use

Every program installed on your computer takes disk space and may run background processes even when you're not using it. Uninstalling programs you haven't opened in months is one of the most effective ways to speed up your system.

Open Settings and go to Apps > Apps & features. You'll see a list of everything installed. Scroll through and look for programs you recognize but don't use—old games, trial software, duplicate browsers, outdated utilities. Click each one and select Uninstall. Windows will walk you through removal.

Pay special attention to antivirus software you may have installed before Windows Defender. Running two antivirus programs at once slows your computer significantly because they scan the same files. If you have Norton, McAfee, Kaspersky, or another third-party antivirus, decide whether you need it. Windows Defender (built into Windows 10) is sufficient for most users and uses fewer resources.

Check how full your hard drive is and make space if needed

Windows 10 runs noticeably slower when your hard drive is more than 85% full, even if you have plenty of RAM. The operating system needs free space to create temporary files, cache data, and manage virtual memory. If you're running out of room, your computer will feel sluggish no matter what else you do.

Open File Explorer and right-click your C: drive (or whichever drive Windows is installed on). Select Properties. You'll see a pie chart showing used and free space. If the blue "Used space" section takes up more than 85% of the circle, you need to free up room.

Start by deleting large files you don't need. Look in your Downloads folder—it often contains old installers and files you downloaded months ago. Check your Documents, Pictures, and Videos folders for duplicates or old backups. You can also move large files to an external drive or cloud storage like OneDrive or Google Drive. If you're still short on space, consider uninstalling more programs or upgrading to a larger hard drive.

Turn off visual effects if your computer is older

Windows 10 includes animations, transparency effects, and shadow effects that look polished but consume processing power. On newer computers with solid-state drives and modern processors, you won't notice the difference. On older hardware, disabling these effects can make the interface feel noticeably faster.

Open Settings and go to System > About. Scroll down and click Advanced system settings. In the window that opens, click the Advanced tab, then click Settings under "Performance". You'll see a list of visual effects. Select Adjust for best performance to turn off all animations and effects at once. Your desktop will look plainer but will respond faster to clicks and window opens.

If you want to keep some effects, select Custom instead and uncheck only the effects you don't care about—like "Animate windows when minimizing and maximizing" or "Show shadows under mouse pointer".

Update drivers and Windows itself

Outdated drivers—especially for your graphics card and chipset—can cause slowdowns and stuttering. Windows updates also include performance improvements and security patches. Keeping both current helps your computer run efficiently.

Open Settings and go to Update & Security > Windows Update. Click Check for updates. Windows will read and install any available updates. You may need to restart your computer. This is worth doing even if you think you're up to date, because Windows sometimes misses updates on the first check.

For drivers, open Device Manager by right-clicking the Start button and selecting Device Manager. Look for any devices with a yellow warning triangle—these have outdated or missing drivers. Right-click the device and select Update driver. Choose Search automatically for updated driver software and let Windows find and install the latest version.

Scan for malware if your computer is still slow

If you've cleaned up your disk, disabled startup programs, and uninstalled unused software but your computer is still sluggish, malware or unwanted software may be running in the background. Malware consumes CPU and memory resources and can make even a new computer feel slow.

Windows 10 includes Windows Defender, which scans for malware. Open Windows Security by clicking the shield icon in your system tray (bottom right of the taskbar) or searching for "Windows Security" in the Start menu. Click Virus & threat protection, then Scan options. Select Full scan and click Scan now. A full scan takes 30 minutes to an hour but checks every file on your computer. If malware is found, Windows Defender will remove it automatically.

If you want a second opinion, you can also run Malwarebytes (a free version is available) or Kaspersky Rescue Disk, which are specialized tools for detecting infections that Windows Defender might miss. These are optional but worth running if you suspect your computer has been compromised.

Frequently Asked Questions

Will disabling startup programs break anything?

No. Disabling a startup program just means it won't launch automatically when you turn on your computer—you can still open it manually whenever you need it. If you disable something important by accident, you can re-enable it the same way in Task Manager.

How much space should I keep free on my hard drive?

Windows runs best when you have at least 15% of your drive free. So if you have a 500 GB drive, keep at least 75 GB empty. If you're consistently above 85% full, your computer will feel noticeably slower, and Windows may struggle to install updates.

Is it safe to delete everything in the Recycle Bin?

Yes. The Recycle Bin holds files you've deleted, and emptying it permanently removes them from your computer. Once you empty it, you can't recover those files, so only do this if you're sure you don't need anything in there. Disk Cleanup will offer to empty it for you.

Should I disable Windows Defender if I have another antivirus?

Yes. Running two antivirus programs simultaneously slows your computer because they both scan every file. Choose one—either Windows Defender (which is free and built in) or a third-party program—and uninstall the other. Windows Defender is sufficient for most users.

What if my computer is still slow after doing all this?

If you've freed disk space, disabled startup programs, and scanned for malware but your computer is still sluggish, the problem may be hardware-related. Your hard drive may be failing, your RAM may be insufficient, or your processor may straightforward be too old for modern Windows 10. At that point, consider upgrading to a solid-state drive (SSD), adding more RAM, or having a technician diagnose the issue.