How to Tell if Your PC Has a Virus (and What to Do)

Signs you might have a virus

• Sudden slowdowns, high CPU/disk usage, or overheating
• Pop‑up ads, new toolbars, or a changed homepage/search engine
• Unknown apps/services, disabled antivirus, or random crashes
• Files renamed/encrypted (ransomware) or missing
• Friends receive spam from your accounts

Quick checks before scanning

• Disconnect from the internet (toggle Airplane mode or unplug Ethernet).
• Back up important files to an external drive or cloud.
• Note suspicious programs installed recently (you’ll remove them later).

Open Task Manager with Ctrl + Shift + Esc; sort by CPU, Memory, and Disk to spot unusual processes.

Confirm with built‑in tools

• Open Windows Security: Win + I → Privacy & Security → Windows Security → Virus & threat protection.
• Check Protection history for recent detections.
• Open Startup apps: Ctrl + Shift + Esc → Startup; disable suspicious entries.
• Review installed programs: Win + I → Apps → Installed apps.

Remove malware safely (step‑by‑step)

1. Boot to Safe Mode with Networking: hold Shift and click Restart → Troubleshoot → Advanced options → Startup Settings → Restart → press the key for Safe Mode with Networking.
2. Run a Quick scan: Win + I → Windows Security → Virus & threat protection → Quick scan.
3. Run an on‑demand scan with a reputable tool (e.g., Malwarebytes Free). Avoid random “PC cleaners”.
4. Remove suspicious programs: Win + I → Apps → Installed apps → uninstall unknown items by recent date.
5. Check browser extensions: remove anything you don’t recognize.
6. Reboot normally and run a Full scan overnight for peace of mind.

If ransomware is suspected (files renamed/encrypted), do not reinstall Windows yet—seek professional help to preserve recovery options.

Need help with safe malware removal? Contact us or Get a Quote.

Fix browser hijackers & pop‑ups

• Reset your browser settings to default.
• Clear cache/cookies for “All time”.
• Chrome’s built‑in Task Manager: press Shift + Esc to find heavy tabs/extensions.

Restore system changes

• Check hosts file if networking seems hijacked: open an elevated terminal (Win + X → Windows Terminal (Admin)) and run:

notepad C:\Windows\System32\drivers\etc\hosts

• Use System Restore if problems started recently: press Win + R → type rstrui → follow the wizard.
• If necessary, Reset this PC (keep files) from Settings → System → Recovery.

Prevention tips

• Keep Windows and apps updated (Win + I → Windows Update).
• Use one reputable antivirus (Windows Security is fine for most users).
• Avoid cracked software and unknown email attachments/links.
• Use a standard (non‑admin) account for daily use when possible.
• Keep backups—cloud or external drive—so you can recover from ransomware.

FAQ

Do I need a paid antivirus?

Not necessarily. Windows Security plus safe browsing habits and on‑demand scans work well for most users.

Can malware survive a reset?

Rarely. A full reset or clean install typically removes persistent threats—back up first.

Is every pop‑up a virus?

No—some are just aggressive ads or extensions. Removing suspicious extensions and clearing data often helps.