Windows 11 PC Running Slow? 14 Ways to Fix It

How to fix a slow Windows 11 PC using Windows performance troubleshooting

Is your Windows 11 PC running slowly, taking too long to start, or freezing when you open apps? Slow performance can have several causes, including too many startup apps, low storage space, high CPU or memory usage, Windows problems, malware, or older hardware.

This guide shows practical ways to find the cause and improve Windows 11 performance without immediately resetting or reinstalling Windows.

Quick Answer:

If your Windows 11 PC is slow, first restart the computer and check CPU, Memory, and Disk usage in Task Manager. Then disable unnecessary startup apps, free up storage, install Windows updates, remove unused software, scan for malware, and check whether your hardware is limiting performance.

Why Is My Windows 11 PC Running Slow?

There is no single cause of a slow Windows 11 PC. Performance can decrease when too many applications run in the background, storage space becomes limited, startup programs consume resources, or a process uses unusually high CPU, memory, or disk resources.

Older computers can also struggle with newer software. If the hardware is already close to its performance limits, software changes may provide only limited improvement.

If your computer has become slow mainly during heavy disk activity, you may also want to check our guide on how to fix 100% Disk usage in Windows.

Before You Start

Save your important work before making system changes. If the problem started recently, note what changed before the slowdown began. For example, you may have installed a new program, driver, Windows update, or hardware device.

Do not disable Windows services randomly. Some system services are required for Windows and installed applications to work correctly.

Fix 1: Restart Your Windows 11 PC

A restart is a simple first step, especially if the computer has been running for a long time.

Restarting can close applications and background processes that are no longer needed and give Windows a fresh session.

To restart:

Go to Start > Power > Restart.

After restarting, open only the applications you need and check whether performance improves.

Fix 2: Check CPU, Memory and Disk Usage in Task Manager

Before changing Windows settings, find out what is actually using your computer's resources.

Press Ctrl + Shift + Esc to open Task Manager.

Select the Processes tab and check the CPU, Memory, and Disk columns.

If one application is continuously using a very large amount of a resource, investigate that application before disabling other Windows features.

You can also select the Performance tab to see overall CPU, memory, disk, and network activity.

Fix 3: Disable Unnecessary Startup Apps

Too many applications starting automatically can make Windows take longer to become responsive after you sign in.

Open:

Settings > Apps > Startup

Turn off startup for applications that you do not need immediately after signing in.

You can also use:

Ctrl + Shift + Esc > Startup apps

Do not disable security software or other applications you know are required for your system.

Fix 4: Free Up Storage Space

A drive with very little free space can contribute to performance problems and can also interfere with Windows updates and other operations.

Open:

Settings > System > Storage

Review the storage categories and remove files you no longer need.

You can also use Storage Sense to automatically clean temporary files and other unnecessary data.

If you want to clean unnecessary files manually, see our guide on how to remove junk files from your computer.

Fix 5: Uninstall Apps You No Longer Use

Unused applications take up storage and some may continue running background processes.

Go to:

Settings > Apps > Installed apps

Find software you no longer need, select the three-dot menu, and choose Uninstall.

Remove only software you recognize. If you are unsure what a program does, research it before uninstalling it.

Fix 6: Install Windows and Driver Updates

Go to:

Settings > Windows Update

Select Check for updates.

If Windows Update itself is not working correctly, follow our detailed guide on how to fix Windows 11 Update not working.

If the slowdown started immediately after a specific Windows update, investigate the update before removing anything. For example, our guide to Windows 11 KB5121003 problems and fixes covers update-related issues separately.

Fix 7: Check for Malware

Malware can consume CPU, memory, disk, or network resources and make a computer appear unusually slow.

Go to:

Settings > Privacy & security > Windows Security > Virus & threat protection

Start with a Quick scan.

If you suspect a serious infection, consider a more thorough scan.

Fix 8: Reduce Unnecessary Background Activity

Some applications continue performing background tasks even when you are not actively using them.

For supported applications, open:

Settings > Apps > Installed apps

Select the application, open Advanced options, and review its background permissions if available.

Do not change background permissions for applications that need to run continuously for your work or security.

Fix 9: Reduce Windows Visual Effects

Windows includes visual effects that can use system resources. On an older or lower-powered PC, reducing these effects may make the system feel more responsive.

Search Windows for:

Adjust the appearance and performance of Windows

Open it and select the Visual Effects tab.

You can select Adjust for best performance or manually disable effects you do not need.

Fix 10: Set Power Mode to Best Performance

Windows 11 provides different power modes. If your priority is performance rather than battery life, you can select a higher-performance mode.

Go to:

Settings > System > Power & battery

Under Power mode, select Best performance when available.

On a laptop, remember that higher performance can increase power consumption, heat, and battery drain.

Fix 11: Optimize Your Drives

Windows includes a built-in tool for optimizing storage drives.

Search Windows for:

Defragment and Optimize Drives

Open the tool, select the appropriate drive, and choose Optimize.

Windows handles drive optimization differently depending on the type of storage device, so avoid applying old hard-drive defragmentation advice to every SSD.

Fix 12: Check for 100% Disk Usage

If Task Manager shows Disk usage close to 100% for long periods, the disk may be contributing to the slowdown.

Check which process is using the disk most heavily in Task Manager.

Possible causes include:

Windows processes
Large file transfers
Windows updates
Antivirus scans
Background applications
A slow or aging storage drive

Do not immediately disable Windows services just because Disk usage reaches 100%. First identify the process causing the activity.

For detailed troubleshooting, read our guide on fixing 100% Disk usage in Windows.

Fix 13: Check RAM and Hardware Limitations

Sometimes Windows is not the main problem. The hardware may simply be limiting performance.

Open Task Manager and select Performance > Memory.

If available memory remains very low while you are using normal applications, the PC may need more RAM.

For older computers, our guide on fixing low memory problems in Windows may also help you identify the cause.

Fix 14: Consider an SSD or RAM Upgrade

If your PC is several years old and software troubleshooting has not produced a meaningful improvement, hardware may be the real limitation.

An upgrade can be more effective than repeatedly changing Windows settings.

Replacing an older HDD with a compatible SSD
Increasing RAM if the system supports it
Checking the health of an aging storage drive
Cleaning excessive dust from desktop cooling systems
Checking laptop cooling and fan operation

Check compatibility before purchasing RAM or replacing a storage drive.

If Your Windows 11 PC Is Still Slow

If the computer remains slow after these steps, look for a specific symptom rather than applying random fixes.

Slow only when opening programs: check storage and RAM.
Slow immediately after startup: check Startup apps.
CPU constantly high: use Task Manager to identify the process.
Memory constantly high: check applications and available RAM.
Disk constantly near 100%: investigate disk usage and storage health.
Slow after a Windows update: identify whether the problem began immediately after the update.
Slow and overheating: check cooling, fans, and ventilation.

If the problem started after another hardware or Windows problem, use the appropriate troubleshooting guide rather than changing unrelated settings. For example, Windows 11 Error Code 43 troubleshooting is more appropriate when a device is reporting that specific error.

Repair Corrupted Windows System Files

Damaged Windows system files can sometimes cause unusual system behavior and performance problems. If you suspect corrupted system files, use Microsoft's built-in DISM and System File Checker tools rather than downloading unknown repair software.

For a detailed step-by-step guide, see how to fix corrupted files in Windows 11 and Windows 10.

Frequently Asked Questions

Why is my Windows 11 PC suddenly so slow?

A sudden slowdown can be caused by a background process, Windows update, application, malware, storage problem, or hardware issue. Start by checking CPU, Memory, and Disk usage in Task Manager.

How can I make Windows 11 faster?

Start by disabling unnecessary startup apps, freeing storage space, installing updates, removing unused applications, checking for malware, and identifying high-resource processes in Task Manager.

Why is Windows 11 slow after startup?

Too many startup applications can delay the time it takes for Windows to become fully responsive. Review Startup apps in Settings or Task Manager.

Does low storage make Windows 11 slow?

Low storage can contribute to performance and update problems. Check Settings > System > Storage and remove unnecessary files.

Can more RAM make Windows 11 faster?

If your PC regularly runs out of available memory during normal use, adding compatible RAM can improve multitasking. The benefit depends on the existing hardware and workload.

Will an SSD make my Windows 11 PC faster?

Replacing an older HDD with a compatible SSD can significantly improve startup and application loading times. The exact improvement depends on the rest of the computer.

Should I use Best Performance mode all the time?

Not necessarily. Best Performance can increase power consumption, heat, and battery drain on laptops. Use it when you need additional performance.

Related Computerdok Guides

Final Thoughts

A slow Windows 11 PC does not always need a reset or a new computer. Start by identifying what is using your system resources, then apply the fix that matches the problem.

If software troubleshooting does not solve the problem, check the hardware. On an older computer, an SSD or RAM upgrade may provide a much larger improvement than changing Windows settings.

Last reviewed: September 2026

Windows 11 PC Running Slow? 14 Ways to Fix It