Signs Your Computer Has Malware

  • Computer suddenly much slower than usual
  • Browser redirects to unexpected websites or shows extra ads
  • Programs opening or closing on their own
  • Antivirus disabled or unable to update
  • Unknown programs in your app list or startup programs
  • Pop-up warnings claiming your computer is infected (often fake — do not click them)

How to Remove Malware on Windows

  1. 1

    Disconnect from the internet

    Unplug your ethernet cable or turn off WiFi. This prevents malware from sending data or downloading additional components while you work.

  2. 2

    Boot into Safe Mode

    Restart and press F8 (or hold Shift while clicking Restart in Windows 10/11) → select Safe Mode with Networking. Safe Mode loads only essential drivers, making it harder for malware to hide.

  3. 3

    Run Windows Defender full scan

    Windows Security (search for it in the Start menu) → Virus and Threat Protection → Scan Options → Full Scan → Scan Now. This scans every file on the computer. Takes 30–90 minutes but is thorough.

  4. 4

    Also run Malwarebytes Free

    Download Malwarebytes from malwarebytes.com (free tier is sufficient). Install and run a full scan. Malwarebytes is excellent at catching threats that Windows Defender misses, particularly adware and potentially unwanted programs. Follow the prompts to quarantine and remove detected threats.

  5. 5

    Check your browser extensions

    Many malware infections manifest as rogue browser extensions. Open your browser → Extensions/Add-ons → remove anything you do not recognise or did not intentionally install.

  6. 6

    Change your passwords

    After removing malware, change passwords for important accounts (email, banking, social media) from a different, clean device if possible. Malware may have captured your credentials.

How to Remove Malware on Mac

  1. 7

    Run Malwarebytes for Mac (free)

    Download from malwarebytes.com → install → run a scan. Malwarebytes for Mac is free and detects the most common Mac malware, adware and potentially unwanted programs. Most Mac malware is adware rather than the destructive type common on Windows.

  2. 8

    Check Login Items and Extensions

    System Settings → General → Login Items — remove anything unfamiliar. Check Safari/Chrome extensions for anything you did not install.

If malware persists after scanningSome sophisticated malware (rootkits) cannot be removed by scanning while the OS is running. In this case, the most reliable solution is to back up your important files to an external drive (scan the drive too), then perform a fresh reinstall of Windows or macOS. This guarantees a clean system.

Frequently Asked Questions

Yes — Macs can and do get malware, though it is less common and generally less damaging than Windows malware. The most common Mac threats are adware (unwanted ads injected into browsers), browser hijackers (changing your search engine), and fake software claiming to be cleaners or antivirus tools. Apple's Gatekeeper and XProtect provide baseline protection but are not infallible.
For most users, no. Windows Defender (built-in, free) combined with Malwarebytes Free for occasional scans provides very good protection. The main paid antivirus products add features like VPN, password managers and identity monitoring — these can be valuable but are not necessary for basic malware protection. Caution and safe browsing habits matter more than which antivirus you use.