How to Fix Windows 11 Slow Performance After Upgrading from Windows 10

Windows 11 can feel slower after an upgrade from Windows 10, especially on PCs that were already carrying years of old apps, startup entries, and leftover system files. The good news is that this is usually fixable without reinstalling Windows.

What Causes This?

A slow Windows 11 upgrade usually happens because the new system is running on top of old Windows 10 clutter. Startup apps, outdated drivers, temporary upgrade files, and background services that were tolerable before can become much more noticeable after the upgrade.

In some cases, Windows is also still finishing post-upgrade tasks like indexing, driver installation, and syncing settings. If those processes combine with low storage space or incompatible software, overall performance can drop fast.

Common Symptoms

• Startup takes much longer than it did on Windows 10
• Apps open slowly or freeze for a few seconds
• High CPU, disk, or memory usage in Task Manager when idle
• File Explorer feels laggy or stutters
• The PC becomes slow after logging in, especially for the first few minutes

How to Fix It Manually

1. Check what is using system resources

   • Open Task Manager with Ctrl+Shift+Esc.
   • Click More details if needed.
   • On the Processes tab, sort by CPU, Memory, and Disk to spot apps causing heavy usage.
   • If a non-essential app is stuck using lots of resources, select it and click End task.

2. Disable unnecessary startup apps

   • In Task Manager, open the Startup apps tab.
   • Look for apps marked High impact.
   • Right-click any app you do not need at startup and choose Disable.
   • Leave security software and touchpad, audio, or graphics tools enabled unless you know they are safe to disable.

3. Remove temporary and upgrade leftover files

   • Open Settings > System > Storage.
   • Click Temporary files.
   • Check items such as Temporary files, Delivery Optimization Files, and Previous Windows installation(s) if you no longer need to roll back.
   • Click Remove files.
   • This can free several GB and reduce background disk activity.

4. Update Windows and device drivers

   • Go to Settings > Windows Update and click Check for updates.
   • Install all available updates, including optional driver updates if relevant.
   • Then right-click Start and choose Device Manager.
   • Expand key categories like Display adapters, Storage controllers, and Network adapters.
   • Right-click a device, choose Update driver, then Search automatically for drivers.

5. Turn off background apps you do not need

   • Open Settings > Apps > Installed apps.
   • Click the three dots next to apps you rarely use and uninstall anything unnecessary.
   • For apps you keep, open Settings > System > Power & battery > Battery usage and review which apps are active in the background.
   • Too many background apps can slow login and general responsiveness.

6. Run system repair scans

   • Open Windows Terminal (Admin) by right-clicking Start and selecting it.
   • Run these commands one at a time:
     1. sfc /scannow
     2. DISM /Online /Cleanup-Image /RestoreHealth
   • Restart your PC after both scans finish.
   • These tools repair damaged system files that can cause sluggish behavior after an upgrade.

7. Restart and test in a clean state

   • Restart the PC after making the changes above.
   • Test startup speed, File Explorer, and a few common apps.
   • If performance improves, the issue was likely startup load, leftover files, or a bad background process.

Fix It Automatically with Kudu

Kudu can scan your PC for upgrade leftovers, bloated startup entries, junk files, and other common causes of slow Windows 11 performance after moving from Windows 10. It helps clean out what you do not need and reduce startup load without digging through multiple Windows menus yourself.

Download Kudu Free →