Slow computer: how to speed up Windows

Find out what is busy before changing anything. Task Manager tells you in ten seconds.

What you seeEverything takes long to open; the mouse pointer keeps spinning

Step 1: look at Task Manager

Press Ctrl + Shift + Esc. On the Processes tab, click the column headings CPU, Memory and Disk in turn to sort by each. See Task Manager for a guide to the screen.

• Memory near 80 to 100%: too many programs or browser tabs for your RAM. Close some; see step 9.
• Disk at 100% for minutes on end: see disk at 100%.
• CPU at 100% from one program: that program is stuck or busy. Select it and choose End task if it is not doing something you asked for.
• Nothing is busy, yet it is slow: think of heat (step 10), a nearly full disk (step 4) or an old hard disk (step 12).

Step 2: restart

Not sleep, not closing the lid: Start › Power › Restart. A restart clears stuck programs and finishes pending updates. Many "slow" computers have simply not been restarted for weeks.

Step 3: stop programs starting with Windows

Settings › Apps › Startup. Turn off everything you do not need the moment you sign in: chat apps, game launchers, updaters, music players. They still work when you open them yourself. Leave security software, touchpad and audio drivers on.

Step 4: free disk space

Windows slows badly when the system drive is nearly full. Keep at least 15 to 20 per cent free. See low disk space.

Step 5: install updates, then stop

Settings › Windows Update › Check for updates. While updates download and install, the computer is slow; let them finish and restart.

Step 6: uninstall what you do not use

Settings › Apps › Installed apps. Remove trial antivirus you never activated, toolbars, "PC cleaners" and "driver updaters". Two antivirus programs at once is a classic cause of slowness; Windows Security alone is enough for most people.

Step 7: scan for malware

Windows Security › Virus & threat protection › Scan options › Full scan.

Step 8: tame the browser

Close tabs you are not using, remove extensions you did not choose (browser menu › Extensions), and turn on the memory-saving feature in the browser's settings.

Step 9: lighten the visual effects

Press the Windows key, type performance and open Adjust the appearance and performance of Windows. Choose Adjust for best performance, then tick "Smooth edges of screen fonts" and "Show thumbnails instead of icons" again. Helpful on older machines.

Step 10: check for heat and the power mode

A hot laptop slows itself to protect its chips. Clean the vents, use it on a hard surface. Then Settings › System › Power & battery › Power mode: Best performance while plugged in.

Step 11: repair system files

Run DISM and sfc from our repair commands page.

Step 12: the hardware answers

• Hard disk to SSD. If Task Manager's Performance tab shows your disk as "HDD", replacing it with an SSD is the biggest improvement money can buy for an old computer: start-up drops from minutes to seconds.
• More RAM. With 4 GB, Windows 11 and a browser are cramped; 8 GB is comfortable for everyday work and 16 GB for heavy use.

If the computer is still slow after all this and has years of clutter, a clean start with Reset this PC is worth an afternoon.

For Windows 11 and Windows 10. Written in November 2026. Menus move between updates; use the search box in Settings if a name differs. Back up important files before any step that resets, repairs a disk or opens the computer. This is an independent guide, not connected with Microsoft.