Speed Up a Slow Windows PC After Removing Malware

    Once malware is removed, follow these steps to clear out leftovers, reset bloated startup, and restore your Windows PC's performance.

    JDCS
    By Jordan Dickson · Reviewed by CSG Security Engineers

    Updated June 2026 · 1 min read

    Even after the actual infection is gone, malware leaves a mess behind: bloated startup, broken network settings, junked-up temp folders and sometimes wrecked browser profiles. Walk through the steps below in order.

    Step 1: Trim startup apps

    1. Open Task Manager (Ctrl + Shift + Esc) and go to Startup apps
    2. Disable anything you do not recognise or do not need at boot
    3. Restart and re-test boot time

    Step 2: Clear temp files and downloads

    1. Press Win + R, type %temp%, press Enter and delete everything you can
    2. Open Settings → System → Storage and run Storage Sense
    3. Empty the Recycle Bin

    Step 3: Reset the network stack

    Some malware tampers with proxy and DNS settings. To reset everything to defaults:
    1. Open Settings → Network & internet → Advanced network settings → Network reset
    2. Click Reset now and let Windows reboot
    3. After reboot, re-enter your Wi-Fi password

    Step 4: Reset affected browsers

    If your browser still feels off (slow, weird search results, leftover extensions) reset it from its own Settings → Reset settings page. This keeps bookmarks and saved passwords but removes hijacker traces.

    Step 5: Verify with one final scan

    Run one more full scan with Malwarebytes and Windows Defender to confirm nothing came back. If both are clean and performance is restored, you are done.

    Was this guide helpful?

    Know someone who needs this? Send them the guide.

    JD

    Written by

    Jordan Dickson

    Founder, CyberSecurityGuides

    Founder of CyberSecurityGuides, writing practical, jargon-free guides that help everyday people recover from and protect against online attacks.

    Reviewed by CSG Security Engineers

    More from Device Security