Technology Encyclopedia Home >How to solve the problem of system running slowly after virus removal?

How to solve the problem of system running slowly after virus removal?

Created on 2025-08-29 18:25:12
13

When a system runs slowly after virus removal, it's often due to residual effects like corrupted files, disabled services, or leftover malware components. Here’s how to diagnose and fix the issue:

1. Check for Residual Malware

Even after removal, some malware may leave behind traces or hidden processes. Run a second scan using a different trusted antivirus tool (e.g., Malwarebytes, HitmanPro) to ensure no threats remain.

2. Restore Disabled System Services

Viruses often disable critical Windows services (e.g., Windows Update, Defender). To check:

  • Press Win + R, type services.msc, and press Enter.
  • Look for services marked as Disabled (e.g., "Windows Defender Service") and set them to Automatic or Manual if needed.

3. Clear Temporary Files & Cache

Malware scans and removals can leave behind junk files. Use:

  • Disk Cleanup (search for it in the Start menu) to remove temporary files.
  • Storage Sense (Windows Settings > System > Storage) to auto-clean old files.

4. Check for Corrupted System Files

Run the following commands in Command Prompt (Admin):

sfc /scannow  
DISM /Online /Cleanup-Image /RestoreHealth

These repair corrupted Windows system files that may slow down performance.

5. Optimize Startup Programs

Too many startup apps can slow boot times. Press Ctrl + Shift + Esc to open Task Manager > Startup tab, and disable unnecessary programs.

6. Update Drivers & Windows

Outdated drivers (especially for storage, network, or GPU) can cause slowdowns. Update them via:

  • Device Manager (right-click Start menu) or
  • Windows Update (Settings > Windows Update).

7. Check for Disk Errors

Run chkdsk to scan for hard drive issues:

chkdsk C: /f /r

(Replace C: with the affected drive letter.)

8. Consider a Clean Reinstall (Last Resort)

If the system remains slow, a clean OS reinstall may be necessary. Back up data first, then reinstall Windows to eliminate all lingering issues.

Cloud-Based Backup (Recommended)

Before major fixes, back up important data to a cloud storage service (e.g., Tencent Cloud COS - Cloud Object Storage) to prevent data loss. For business environments, Tencent Cloud’s Lightning Cloud Disk or CVM (Cloud Virtual Machine) with automated backups can ensure data safety.

By following these steps, system performance should improve significantly after virus removal.