Speed Up a Slow Windows Computer

Restart properly

Shutting down doesn't fully reset Windows, because Fast Startup saves part of it to disk for a quicker start next time. Choosing Restart from the Start menu clears everything out, and often fixes a computer that has become slow after being on for days.

See what's using your computer

Press Ctrl + Shift + Esc to open Task Manager. On the Processes page, click the CPU, Memory or Disk heading to put the busiest programs at the top.

• One program near 100% Close it, or right-click it and choose End task if it has stopped responding.
• Memory always above 90% The computer doesn't have enough memory (RAM) for what you're doing. Close some browser tabs, or think about adding more memory.
• Disk always at 100% Usually a sign of an old hard drive. An SSD upgrade makes a huge difference.

Stop programs starting automatically

Many programs set themselves to start with Windows and run in the background. In Task Manager, open Startup apps and look at the Startup impact column. Right-click anything you don't need straight away and choose Disable. The program still works; it just won't start until you open it.

Free up disk space

Windows slows down when the drive is nearly full. Open Settings > System > Storage to see what's using the space. Try to keep at least 15% of the drive free.

• Cleanup recommendations On the Storage page, lists temporary files, large files and unused apps you can safely remove.
• Storage Sense Turn it on to empty the Recycle Bin and clear temporary files automatically.
• Downloads folder Often full of old installers and files you no longer need.

cleanmgr

Check for updates and viruses

• Windows Update Open Settings > Windows Update and install anything waiting. Updates often include speed and stability fixes. If they won't install, see Fix Windows Update Problems.
• Scan for malware Open Windows Security > Virus & threat protection and run a Quick scan. Malware can slow a computer right down.

Still slow? Check the hardware

Older computers often just need an upgrade rather than a replacement:

• Replace the hard drive with an SSD The single biggest improvement for an older computer. Start-up times can drop from minutes to seconds.
• Add more memory 8 GB is the minimum for Windows 11, and 16 GB is better if you keep lots of programs or browser tabs open.

We can tell you whether an upgrade is worthwhile and fit it for you. More on computer repair.

Quick reference