Why your PC is running slow and how to speed it up

Slow to open programs, or lagging when you click? Start with the quickest, lowest-risk fixes and move on to the ones that take more time. They apply to Windows 11 and Windows 10.

Before you start

A PC usually slows down for a handful of ordinary reasons: too many programs open at once, too many programs starting with Windows, a nearly full drive, pending updates, or unwanted software. Less often the cause is an aging part, such as a drive or too little memory (RAM).

The fixes below need no downloads and no special tools. Allow about 20 minutes in total. Test the PC after each fix and stop when it feels normal again.

Try these fixes in order

Fix 1: Close programs and restart

This takes about 3 minutes. A restart clears memory and stops background tasks that built up over days.

1. Save your work in every open program.
2. Close programs and browser tabs you are not using.
3. Select Start, select the Power button, then select Restart. Choose Restart rather than Shut down for this test.
4. After the PC starts, open only the programs you need and check the speed.

Fix 2: See what is using your PC

Task Manager shows which programs are working hardest. This takes about 5 minutes and changes nothing.

1. Press Ctrl + Shift + Esc to open Task Manager. If you see a small window, select More details.
2. On the Processes tab, select the Memory column heading, then the CPU and Disk headings. Each click sorts the list so the biggest user is at the top.
3. Look at the top few entries. A web browser with many tabs is a common cause.
4. If a program you do not need is near the top, select it and select End task. Save your work first. Do not end items you do not recognize without searching for their name on the maker's support site.
5. Select the Performance tab. Note whether Memory, CPU or Disk is close to full while the PC is slow. This points to the next fix.

Fix 3: Turn off startup apps

Programs that start with Windows slow down both startup and everyday use. This takes about 5 minutes. The full steps are in manage startup programs and speed up boot. In short:

1. Open Settings then Apps then Startup.
2. Switch Off the apps you do not need at sign-in, such as chat or game launchers. The toggle stops the app from launching automatically. The program stays installed.

Fix 4: Free up disk space

A drive that is nearly full slows Windows and blocks updates. Check it in Settings then System then Storage. If space is short, follow how to free up disk space on Windows. Microsoft's own pages point to Storage Sense and, on Windows 11, Cleanup recommendations.

Fix 5: Install Windows updates

1. On Windows 11, open Settings then Windows Update. On Windows 10, open Settings then Update & Security then Windows Update.
2. Select Check for updates.
3. Let any updates download and install, then restart when asked.

The PC can feel slow while it installs updates in the background. If an update seems stuck, see Windows Update stuck or failing.

Fix 6: Scan for malware

Unwanted software can use a lot of your PC's power. Windows Security is built in and free. This takes 5 to 15 minutes.

1. On Windows 11, open Settings then Privacy & security then Windows Security. On Windows 10, open Settings then Update & Security then Windows Security.
2. Select Open Windows Security, then Virus & threat protection. On Windows 11, select Quick scan. On Windows 10, select Quick scan under Current threats.
3. Follow any on-screen prompts. For a deeper scan, see how to run a malware scan.

Fix 7: Reduce background activity and visual effects

These changes give smaller gains, so try them last. Microsoft lists them as ways to improve performance.

• Visual effects: Select the search box on the taskbar, type Adjust the appearance and performance of Windows, and open it. On the Visual Effects tab, select the option that adjusts for performance, then OK. Windows will look plainer.
• Power mode on Windows 11: Open Settings then System then Power & battery and set Power mode to the top setting, the one named for performance. On a laptop this drains the battery faster and can make the PC run warmer.
• Power plan on Windows 10: Open Settings then System then Power & sleep, select Additional power settings, and select Show additional plans if needed, and choose the High performance plan if it is listed.

If it is still slow

If none of the fixes helped, the cause may be the hardware or its age.

• Memory nearly full all the time: In Task Manager, the Performance tab shows Memory close to full even after a restart. The PC may not have enough RAM for what you run. Whether RAM can be added depends on the model, so check the maker's support page for your PC.
• Heat and fan noise: A hot PC slows itself down to protect its parts. See PC overheating and loud fans.
• Programs freezing: If one program is slow or stops responding, see app not responding or crashing.
• Back up your files if the PC slows suddenly or makes clicking noises. See how to back up your files.

Use the support page on the PC maker's website for hardware advice for your exact model.

Frequently asked questions