Why Your PC Is Slow After a Windows 11 Update (and How to Fix It)

     Your PC felt fine yesterday. After a Windows 11 update, it’s sluggish: apps open slowly, the fan runs, and the mouse lags. This is common, and it usually has simple causes: Windows is still finishing background work, old drivers don’t match the new update, or too many apps start with Windows.

Quick answer

    Restart twice, give Windows 30 to 60 minutes to finish background tasks, then check Task Manager to see what is using your CPU, memory or disk.

Fix 1: Restart and wait

    After a big update, Windows indexes files and optimizes the system in the background. Restart your PC, leave it plugged in and connected to the internet for an hour, then test again.

Fix 2: See what is using your resources

1. Press Ctrl + Shift + Esc to open Task Manager.
2. On the Processes tab, click the CPU, Memory and Disk headings to sort by use.
3. If one app is using a lot constantly, close it, update it, or uninstall it.

[Screenshot: Task Manager sorted by CPU]

Fix 3: Turn off apps you don’t need at startup

Open Task Manager → Startup apps, right-click anything you don’t need immediately, and choose Disable. Our startup guide covers this in detail.

Fix 4: Set a performance power mode

Go to Settings → System → Power & battery and set Power mode to Best performance while plugged in. On a laptop, this uses more battery, so switch back when you’re on battery.

Fix 5: Reduce visual effects

1. Press Win + R, type sysdm.cpl, and press Enter.
2. Open the Advanced tab and click Settings under Performance.
3. Choose Adjust for best performance, or untick only the effects you don’t need, then click OK.

You can also turn off Transparency effects under Settings → Personalization → Colors.

Fix 6: Install driver and Windows updates

A new Windows version sometimes needs newer drivers. Run Settings → Windows Update and check Advanced options → Optional updates for driver updates. Graphics and chipset drivers matter most, and your PC maker’s website often has the newest versions.

Fix 7: Scan and repair

• Run a full scan in Windows Security.
• Repair system files with the SFC and DISM commands.
• Make sure at least 15% of your drive is free.

If it’s still slow