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Likely fix

Fix: High CPU usage on Windows

High CPU usage means one or more apps or background processes are using too much processor power, which can make the whole PC feel slow.

Quick answer

Open Task Manager, sort by CPU, close the app using the most CPU if it is safe, then restart the PC and check for updates.

Important warning

Do not end Windows system processes unless you know what they are. Restarting is safer than killing unknown processes.

Try this

  1. 1 Press Ctrl + Shift + Esc to open Task Manager.
  2. 2 Click the CPU column to sort by highest usage.
  3. 3 Identify the app or process using the most CPU.
  4. 4 Close normal apps you recognize and are not using.
  5. 5 Restart the PC.
  6. 6 Install pending Windows and app updates.
  7. 7 If one app always causes high CPU, update it, reinstall it, or remove it.

Common causes

A frozen or buggy app.

Browser tabs or extensions.

Windows updates or indexing.

Antivirus scan.

Game launcher, video editor, or sync app running in the background.

What to check next

  • Check which app is at the top of Task Manager.
  • Check whether CPU drops after closing the app.
  • Check whether the issue returns after restart.
  • Check whether Windows Update is active.
  • Check whether the PC is also overheating.

FAQ

What is high CPU usage?

High CPU usage means the processor is busy. If it stays high for a long time, apps may lag, fans may get loud, and the PC may feel slow.

Is 100% CPU usage bad?

Short bursts are normal. Constant 100% CPU usage means something is using too much processor power or the PC is underpowered for the task.

Should I end tasks in Task Manager?

Only end normal apps you recognize. For unknown system processes, restarting the PC is safer.

Related fixes

Fix: PC is hot or the fan is loud

A hot PC or loud fan can make the system slow because the processor reduces speed to protect itself from heat.

Fix: PC is slow and you are not sure why

When you are not sure why a PC is slow, start with the safe checks: restart, Task Manager, startup apps, free storage, updates, browser tabs, and overheating.

Fix: PC takes too long to start

Slow startup is usually caused by too many startup apps, pending updates, an old hard drive, background sync apps, or a system that was not fully shut down.

Fix: High memory usage on Windows

High memory usage usually happens when too many apps, browser tabs, background tools, or large programs are open at the same time.

Fix: PC is slow because storage is almost full

A Windows PC can slow down when the drive is almost full because updates, temporary files, browser caches, and apps need free space to work properly.

Fix: Browser is slow

A slow browser is usually caused by too many tabs, heavy extensions, cached data problems, low memory, background downloads, or the internet connection itself.