Hi
yuhiLee,
This is a common problem after a Windows 11 update, and in many cases it is fixable.
What may be causing it
The most likely causes are:
- Background post-update tasks such as indexing, Windows Update cleanup, and driver optimization
- Driver issues after the update, especially storage, chipset, or graphics drivers
- Corrupted system files introduced during or after the update
- High RAM usage because 8 GB RAM can feel tight on Windows 11, especially with multiple apps open
- Low free SSD space or heavy disk usage in the background
- A bad update installation or a startup service now causing delays
Start with these checks
1. Check Task Manager during the slowdown
- Press
Ctrl + Shift + Esc.
- Open the Processes tab.
- Sort by CPU, then Memory, then Disk.
- Watch for any process staying unusually high for several minutes.
Look especially for:
- Windows Modules Installer Worker
- Antimalware Service Executable
- SearchIndexer.exe
- A third-party antivirus
- A driver utility or manufacturer updater
If one process is consistently high, that gives us the best clue.
2. Check free SSD space
- Open Settings.
- Go to System > Storage.
- Make sure you have at least 20 GB free, preferably more.
If the SSD is nearly full, startup and app launching can slow down a lot.
3. Let Windows finish post-update maintenance
If the update was installed very recently:
- Leave the PC powered on for 30 to 60 minutes.
- Keep it connected to power.
- Avoid opening many apps during that time.
- Restart once after that.
Sometimes the system is still finishing update-related work in the background.
Repair Windows system files
Before deeper changes, I recommend creating a
restore point.
4. Run DISM and SFC
- Right-click Start.
- Open Terminal (Admin) or Command Prompt (Admin).
- Run these commands one at a time:
Code:
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow
- Restart the PC after both complete.
Expected result
- If corrupted system files are involved, boot time and app launching may improve after restart.
Check for driver problems
5. Update chipset, storage, and graphics drivers
Do
not rely only on Windows Update for this.
- Visit your PC or motherboard manufacturer's support page.
- Download and install the latest:
- Chipset driver
- Storage / NVMe / Intel RST / AMD SATA driver
- Graphics driver
- Restart the system.
This is especially important if the slowdown started immediately after the update.
Test with a clean boot
This helps identify whether a background service is causing the lag.
6. Perform a clean boot
- Press
Win + R, type msconfig, and press Enter.
- Open the Services tab.
- Check Hide all Microsoft services.
- Click Disable all.
- Open the Startup tab and click Open Task Manager.
- Disable all startup items.
- Restart the PC.
If performance improves
One of the disabled non-Microsoft services or startup apps is the cause.
To undo this
- Open
msconfig again.
- Re-enable services gradually.
- Re-enable startup items a few at a time until the slowdown returns.
Check disk and memory pressure
7. Review Resource Monitor
- Press
Win + R.
- Type
resmon and press Enter.
- Check:
- Disk tab for sustained high active time
- Memory tab for hard faults and near-full memory use
If memory usage is constantly high, your
8 GB RAM may now be a bottleneck after the update. That would explain lag when switching tasks.
If the issue started immediately after one update
8. Uninstall the latest quality update as a test
Only do this if the slowdown began right after the update.
- Go to Settings > Windows Update > Update history > Uninstall updates.
- Remove the most recent quality update.
- Restart and test performance.
Warning: This removes recent fixes, so use it mainly as a diagnostic step.
My recommended order for you
Please try these in order:
- Check Task Manager for high CPU, disk, or memory usage
- Confirm how much free SSD space you have
- Run:
Code:
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow
- Update chipset, storage, and graphics drivers
- Perform a clean boot
- If needed, test by uninstalling the latest update
A few questions so I can narrow this down
- When exactly did the slowdown begin — immediately after a specific update, or gradually?
- What is your CPU model?
- How much free space is left on the SSD?
- In Task Manager, which process shows the highest CPU, Memory, or Disk usage during the slowdown?
- Are you using Windows Defender only, or a third-party antivirus?
- Does the system also feel slow in Safe Mode?
If you reply with those details, I can help you pinpoint whether this is a
driver issue,
update issue, or simply
memory/disk pressure.
