A slow computer is usually slowed by too many startup programs, a nearly full drive, pending updates, or a session that has been running for days. Work through these steps in order, starting with a restart, and check whether things feel faster after each one.
Steps
Restart the computer. Select Start, then Power, then Restart. A restart clears temporary memory, ends stuck background processes, and finishes pending updates. Shutting the lid or choosing Sleep does not do the same job.
Check for Windows updates. Open Settings, select Windows Update, then select Check for updates. Install anything offered, then restart if asked. On Windows 10, the path is Settings, then Update and Security, then Windows Update.
Turn off unneeded startup apps. Open Settings, select Apps, then Startup. Turn off apps you do not need the moment you sign in, such as game launchers, chat apps, and cloud storage you rarely use. Keep security software turned on.
Uninstall programs you no longer use. Open Settings, select Apps, then Installed apps. Sort by size, select a program you recognize and no longer need, select the three dots next to it, then Uninstall. On Windows 10, this list is called Apps and features.
Free space on the drive. Open Settings, select System, then Storage. Select Temporary files, tick the categories you are happy to remove, such as Temporary files and Recycle Bin, then select Remove files. A drive that is nearly full slows the whole system down.
Check Task Manager for one hungry program. Press Ctrl, Shift, and Esc together to open Task Manager. Select Processes, then select the CPU or Memory column to sort by use. If one app is using most of the processor or memory, close it from inside the app, or select it and choose End task.
Restart once more and compare. After updates, startup changes, and cleanup, restart again. If the computer is still slow with only a browser open, the drive or memory may be the limit, and a hardware upgrade is the next thing to look into, not another setting.
Do not install registry cleaners or so-called speed booster programs. They do not make a modern Windows computer faster, and they can delete settings your system needs.
If it is still slow after these steps
Run a scan with the built-in Windows Security app: open Settings, select Privacy and security, then Windows Security, then Virus and threat protection, and choose Quick scan. Malware running in the background is a common cause of a computer that suddenly got slow. Also check that the drive is not almost full, aim to keep at least 10 percent of the drive free.
About this guide
This guide covers the fixes that help most Windows 11 and Windows 10 computers, in the order that wastes the least of your time. Menu names differ slightly between Windows 11 and Windows 10, and both versions are noted where they differ.
Common questions
How often should I restart my computer? At least once a week. A restart clears memory and finishes updates, and it is the single quickest fix for a computer that has gradually become sluggish.
Will turning off startup apps break anything? No. Turning an app off in Startup only stops it launching at sign-in. You can still open it yourself at any time, and you can turn it back on in the same list.
Does a slow computer mean I need a new one? Not usually. A full drive, too many startup apps, pending updates, or one misbehaving program are more common causes. If the computer is still slow after this guide, and it has a spinning hard drive or only 4 GB of memory, a hardware upgrade is worth pricing before replacing the whole machine.
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