What slows down Windows 10 and how to fix it

Windows 10 slows down because of three things: files you no longer need taking up space, programs running in the background you forgot about, and a hard drive that has fragmented over time. You can fix all three without buying anything or reinstalling Windows. The fastest results come from removing old programs, stopping unnecessary startup items, and clearing temporary files — in that order.

Most people notice slowness first when opening programs or switching between windows. That usually means your hard drive is full or your RAM is overloaded with background tasks. A full drive makes Windows work harder to find space for temporary files. Too many startup programs means your computer is doing work you never asked for the moment it turns on.

Key Takeaways

  • Uninstall programs you no longer use through Settings > Apps > Apps & features, which removes files and frees up disk space faster than deleting shortcuts.
  • Disable startup programs by right-clicking the taskbar, selecting Task Manager, clicking the Startup tab, and unchecking items you do not need running when Windows starts.
  • Delete temporary files using Disk Cleanup (search "Disk Cleanup" in the Start menu) or by manually clearing the Temp folder at C:\Users\[YourUsername]\AppData\Local\Temp.
  • Check how much free space you have left — Windows needs at least 10 to 15 percent of your drive empty to run smoothly, so if you have less, delete large files or move them to external storage.
  • Run Windows Update to the latest version, because updates often include performance fixes that work automatically once installed.

Uninstall programs you actually do not use

Programs you installed once and forgot about still run in the background and take up disk space. Open Settings by pressing Windows key + I, then go to Apps > Apps & features. Scroll through the list and look for anything you have not opened in months. Click each one and select Uninstall, then follow the prompts.

Uninstalling is faster than deleting because it removes not just the program folder but also registry entries and temporary files the program created. When you just delete a folder, Windows still remembers the program exists and wastes time looking for it. Uninstalling tells Windows to forget it completely.

Start with programs you recognize but do not use: old games, trial software, duplicate media players, or tools you tried once. Leave Windows system programs alone — they have names like "Windows Defender" or "Windows Update" and removing them can cause problems.

Turn off programs that start automatically

Every program you install asks Windows permission to run when your computer starts. Most of them you will never notice, but together they add up. Right-click the taskbar at the bottom of your screen and select Task Manager. Click the Startup tab at the top.

You will see a list of programs with a Status column showing Enabled or Disabled. Right-click any program you do not need running the moment Windows starts — common ones are Adobe Reader, Spotify, Discord, or Dropbox — and select Disable. You can still open these programs manually whenever you want; you are just stopping them from launching automatically.

Leave items alone if you do not recognize the name. Some are Windows services you need. If you disable something and Windows stops working correctly, open Task Manager again, right-click the item, and select Enable to turn it back on.

Clear temporary and cache files

Windows and your programs create temporary files constantly — copies of documents you were editing, web browser cache, installation leftovers. These files pile up and waste space. The easiest way to delete them is through Disk Cleanup. Press Windows key + S, type "Disk Cleanup", and open it.

Disk Cleanup will scan your drive and show you categories of files you can delete: Temporary files, Recycle Bin, Temporary internet files, and others. Check the boxes next to each category, then click Delete Files. This is safe — these are files Windows and programs created automatically, not your documents or photos.

If Disk Cleanup does not show much to delete, you can manually clear the Temp folder. Press Windows key + R, type %temp% and press Enter. A folder will open. Select all files (Ctrl + A), then delete them. Windows may say some files are in use — that is normal. Delete what you can and move on.

Check your disk space and move large files

Windows needs breathing room to work. If your drive is more than 85 percent full, performance drops noticeably. Right-click your C: drive in File Explorer and select Properties to see how much space you have left. If the blue bar is mostly full, you need to free up space.

The fastest way is to move large files you do not use often to an external hard drive or USB stick. Videos, old photos, and archived documents take up the most space. You can also delete old downloads — most people never look at their Downloads folder again after a few weeks.

If you have less than 10 gigabytes free, Windows will start running very slowly because it cannot create temporary files it needs. Aim for at least 15 to 20 gigabytes free on a typical computer.

Update Windows to the latest version

Microsoft releases updates that fix performance problems and security issues. Open Settings (Windows key + I), go to Update & Security > Windows Update, and click Check for updates. If updates are available, Windows will read and install them. You may need to restart your computer.

Updates happen automatically in the background, but checking manually ensures you have the latest version. Some updates specifically target slowness or battery drain, so staying current often improves speed without you doing anything else.

Disable visual effects if your computer is very old

Windows 10 includes animations and transparency effects that look nice but use processing power. If your computer is more than five years old or has less than 4 gigabytes of RAM, turning these off can help. Right-click This PC or My Computer on your desktop, select Properties, then click Advanced system settings on the left.

Click the Settings button under Performance. Select Adjust for best performance, which turns off most animations. You can also manually check or uncheck individual effects — for example, you might keep window animations but turn off fade effects. Click explore and OK.

This change is most noticeable on older laptops or computers with slower processors. Newer machines will not see much difference because they have enough power to run effects and programs at the same time.

Frequently Asked Questions

How often should I clean up my PC?

Run Disk Cleanup and check your startup programs once a month if you install software regularly, or every three months if you do not. Uninstall programs as soon as you know you will not use them. The sooner you remove something, the less space it wastes and the fewer background processes it runs.

Will cleaning up my PC delete my files or photos?

No. Disk Cleanup only removes temporary files, cache, and the Recycle Bin. Uninstalling programs removes only the program itself, not your documents. Your personal files stay untouched. If you are nervous, you can move important files to an external drive first as a backup.

What if my PC is still slow after I do all this?

Slowness can also come from a failing hard drive, overheating, or a virus. Run Windows Defender (built into Windows 10) by searching for it in the Start menu and clicking Scan options, then Full scan. If the scan finds nothing and your computer is still slow, the hard drive may be failing and you may need to replace it.

Is it safe to disable all startup programs?

Most startup programs are safe to disable, but some Windows services need to stay on. If you do not recognize a program name, leave it alone. You can always re-enable it later if something stops working. Start by disabling only programs you recognize and do not need, like Spotify or Discord.

Do I need to defragment my hard drive?

If you have a traditional hard drive (not an SSD), defragmentation can help, but Windows 10 does this automatically in the background. You do not need to do it manually. If you have an SSD, do not defragment — it can actually shorten the drive's lifespan.