Start with the pattern of the delay
Identify when the computer slows down before changing settings, then test after each check.
Step 1 of 9
In this guide
Pin down when the slowdown happens
Pin down when the slowdown happens
Notice when the delay appears: just after Windows starts, in one app, while browsing, opening files, using several apps together, or even when nothing is open.
Also note complete freezes, error messages, unexpected restarts, unusual noises, or slowness that happens only with an internet connection. These differences help separate Windows, an app, storage and hardware problems.
Check whether the computer is running normally. If it is, you can stop here.
Restart before changing settings
Restart before changing settings
- Save your work and close the open apps.
- Choose Start > Power > Restart.
- Let Windows finish starting, then try using the computer again.
Check whether the computer is running normally. If it is, you can stop here.
Check what is using resources
Check what is using resources
From Start, select the search box, type Task Manager and open the result. If a small view appears, choose More details, then select Processes.
The CPU, Memory, Disk and Network columns show resource use. Click a heading to sort by that resource.
- CPU: if an app is using a very high amount, check that you recognise it and close it normally. If it will not respond, right-click it and choose End task. Leave unfamiliar tasks alone, particularly Windows system processes.
- Memory: identify the heaviest apps, save your work, and close apps and browser tabs you do not need. Restart Windows if memory use stays high.
- Disk: if activity stays near 100%, review the busiest apps and close unused ones. Wait a few minutes for activity to settle; restart if it remains at 100%.
- Network: for slowness during downloads, synchronising or browsing, check which apps are busy. Pause unneeded downloads or cloud synchronisation, close apps using the connection unnecessarily, then test again.
Open apps and browser tabs use processing power and memory. Review the taskbar and close unused apps. In the browser, close unneeded tabs and extra windows, then test again. If many tabs trigger the slowdown, keep fewer open or restart the browser.
Check whether the computer is running normally. If it is, you can stop here.
Reduce unnecessary startup apps
Reduce unnecessary startup apps
Too many apps launching at login can slow the computer. In Task Manager, select Startup apps on the left and review the list and Startup impact column. Select an app you do not need at startup and choose Disable.
This stops its automatic launch; it does not uninstall the app. Restart Windows after making changes.
Do not disable:
- Windows Security or any other security software
- Hardware drivers
- Touchpad or keyboard utilities
- Required backup software
- Workplace-required programs
- Apps you cannot identify
Check whether the computer is running normally. If it is, you can stop here.
Check the free storage
Check the free storage
Very little free space can slow Windows and apps; check Settings > System > Storage, where Local Disk (C:) is usually the main Windows drive.
If it is nearly full, use our disk space guide for cleanup, then restart Windows.
Check whether the computer is running normally. If it is, you can stop here.
Test an app that runs slowly
Test an app that runs slowly
- Close the affected app, restart Windows and open it again.
- Try a small or simple file.
- Find the app's update option and install updates through its official updater.
- Restart the app.
If only one file opens slowly, it may be large or damaged. Compare it with another file in the same app.
Check whether the computer is running normally. If it is, you can stop here.
Check Windows updates, drivers and system files
Check Windows updates, drivers and system files
Windows updates can address performance and compatibility faults. Open Start > Settings > Windows Update > Check for updates. Wait for the check, install available updates and restart if requested. Check again afterwards until Windows reports it is up to date. Keep a laptop plugged into power during installation.
Look for relevant hardware drivers under Settings > Windows Update > Advanced options > Optional updates.
Device Manager can flag a driver error with a yellow exclamation-mark triangle; our software and driver update guide covers both checks for hardware such as graphics, storage or network devices.
Damaged Windows files can also cause slowness or unexpected behaviour. To run the system-file scan:
- Open Start and type Command Prompt.
- Right-click its result and choose Run as administrator. Select Yes if User Account Control asks.
- Enter sfc /scannow and press Enter.
- Leave the window open until the scan finishes, then restart Windows.
Check whether the computer is running normally. If it is, you can stop here.
Scan for malware
Scan for malware
Malware running in the background can make a computer slow. Run a full scan with the security program on your computer.
- Your own security program (such as Norton or McAfee): open it and run a full scan from there.
- Windows Security only: open Start > Windows Security > Virus & threat protection > Scan options, choose Full scan and select Scan now.
A full scan can take a while, so let it finish. Do not delete your security software.
Check whether the computer is running normally. If it is, you can stop here.
Review hardware, power and ventilation
Review hardware, power and ventilation
If the software checks have not helped, hardware may be limiting performance. Check for a traditional hard disk rather than an SSD, little installed memory, overheating, a failing drive, a fan that runs constantly, dusty vents, or a battery or power setting that limits performance.
Open Start > Settings > System > Power & battery > Power mode and choose Balanced or Best performance to suit your needs. Best performance can use more laptop battery power.
Keep the air vents clear. Move the computer off bedding or cushions and onto a hard, flat surface. Let it cool, then restart Windows and test again.
Leave the case and internal components alone unless you are qualified to work on them.
Check whether the computer is running normally. If it is, you can stop here.
Book IT supportFrequently asked questions
What should I note before changing settings?
Record when the delay happens: at startup, in one app, with files or browsing, with several apps, or all the time. Note freezes, errors, restarts, unusual noises and any link to internet use.
What should I check in Task Manager?
Compare CPU, Memory, Disk and Network, sorting by a column to find the busiest apps. Close recognised apps you do not need. Leave unfamiliar tasks and Windows system processes alone.
Does disabling a startup app remove it?
No. It stops the app opening automatically when Windows starts. Keep required security, drivers, keyboard or touchpad tools, backup and workplace programs enabled, along with anything you cannot identify.
Why does the computer slow down with lots of browser tabs?
Open tabs and apps use processing power and memory. Close tabs and extra browser windows you no longer need, then compare performance. If it happens only with many tabs, use fewer or restart the browser.
What if only one file is slow?
Try the app with a small, simple file and compare another file. One unusually slow file may be very large or damaged; the app may also need an update through its official updater.
