Start with a full scan using Windows Defender or your antivirus program
The fastest way to find and remove a virus is to run a complete scan with the antivirus software already on your laptop. Windows Defender comes built into Windows 10 and 11 at no cost, and it catches most common viruses without you installing anything else. If you have a different antivirus program (Norton, McAfee, Avast, Bitdefender), use that instead — do not run two antivirus programs at the same time, as they interfere with each other.
Open Windows Defender by typing "Windows Defender" into your search box and clicking "Windows Security". Click "Virus & threat protection" on the left side. Under "Current threats", click "Scan options", then select "Full scan" and click "Scan now". This scan takes 30 minutes to several hours depending on how much is on your laptop, so plug in your power adapter and let it run without interrupting it.
When the scan finishes, Windows Defender will show you what it found. Click "Remove" or "Quarantine" for each threat it lists. Quarantine moves the file to a safe location where it cannot run; remove deletes it. Either option stops the virus from working. Restart your laptop when prompted.
Key Takeaways
- Run a full scan with Windows Defender or your existing antivirus program — this finds and removes most viruses without extra software.
- If a scan finds nothing but your laptop still behaves oddly, restart in Safe Mode and scan again, because some viruses hide from normal scans.
- Never run two antivirus programs at the same time; they conflict with each other and slow your laptop down.
- If your laptop will not start or antivirus will not open, use a bootable antivirus tool on a USB drive created from another computer.
- After removing a virus, change your passwords from a different device, because viruses often steal login information.
Restart in Safe Mode if the virus blocks your antivirus program
Some viruses prevent Windows Defender or other antivirus programs from opening. If you cannot launch your antivirus program, restart your laptop in Safe Mode, where Windows loads only essential programs and the virus cannot block you.
On Windows 10 or 11, hold down the Shift key and click the power button in the bottom right corner. Select "Restart". Your laptop will restart and show a menu with options. Click "Troubleshoot", then "Advanced options", then "Startup Settings", then "Restart". When your laptop restarts again, press 4 or F4 to enter Safe Mode with Networking (the networking option lets you download updates if needed).
Once in Safe Mode, open Windows Defender the same way as before and run a full scan. Safe Mode prevents the virus from running, so the scan can find and remove it. After the scan completes and you restart normally, your antivirus should work again.
Use a bootable antivirus tool if your laptop will not start
If your laptop will not boot into Windows at all, or if it boots but freezes immediately, you need a bootable antivirus tool — a program that runs before Windows loads. Kaspersky Rescue Disk and Bitdefender Rescue Disk are both free and work on any laptop.
You will need a second computer and a USB drive with at least 1 GB of space. Go to the Kaspersky Rescue Disk website on the working computer, download the ISO file, and follow their instructions to create a bootable USB drive. Plug the USB drive into your infected laptop, restart it, and press F12, F2, or Delete during startup (the key varies by laptop model — watch the screen for a message like "Press F12 to enter boot menu"). Select the USB drive from the boot menu.
The antivirus tool will load and scan your laptop automatically. This process takes longer than a normal scan because it is checking every file on your hard drive, but it finds viruses that hide from Windows. When the scan finishes, the tool will remove the threats and you can restart normally into Windows.
Check your browser and remove unwanted extensions
Some viruses install fake toolbars or extensions in your web browser that redirect your searches, show pop-up ads, or steal your browsing history. Even if a full scan removes the main virus, these extensions can stay behind and cause problems.
Open your browser (Chrome, Firefox, Edge, or Safari) and look for any extensions or add-ons you do not recognize. In Chrome, click the three-line menu in the top right, go to "More tools", then "Extensions". Look for anything unfamiliar and click the trash icon to remove it. In Firefox, click the menu button, select "Add-ons and extensions", find suspicious items, and click "Remove". In Edge, click the three-dot menu, select "Extensions", and remove anything you did not install yourself.
Also check your browser's home page and search engine settings. If they have changed to something you did not set, change them back. In Chrome, click the menu, go to "Settings", click "Search engine" on the left, and make sure Google (or your preferred search engine) is selected. Do the same in other browsers.
Change your passwords from a different device
Viruses often log your keystrokes or steal saved passwords, so changing your passwords is essential even after you remove the virus. Do this from a different device — a phone, tablet, or another computer — so the virus on your laptop cannot see the new passwords as you type them.
Start with your email password, because your email account is the key to resetting everything else. Go to your email provider's website (Gmail, Outlook, Yahoo), sign in, find the password or security settings, and change your password to something long and unique. Then change passwords for your bank, credit card, social media, and any other accounts that hold sensitive information. Use a password manager like Bitwarden or 1Password to store these new passwords securely.
If you see charges on your bank or credit card that you did not make, contact your bank immediately. Many banks can reverse fraudulent charges if you report them quickly.
Keep your laptop protected after removing the virus
Once you have removed the virus, take steps to prevent another infection. Keep Windows and all your programs up to date by turning on automatic updates. In Windows 10 or 11, go to Settings, click "Update & Security" or "System", then "Windows Update", and make sure "Install updates automatically" is on.
Be cautious about what you download and where you download it from. Viruses often hide in cracked software, pirated movies, or files from untrusted websites. Stick to official sources: the Microsoft Store for Windows programs, the Chrome Web Store for browser extensions, and the official websites for programs you need.
Do not open email attachments from people you do not know, and be suspicious of links in emails that ask you to verify your password or account information. These are common ways viruses spread. If an email looks odd or urgent, contact the sender through a different method (phone call or text) to confirm they actually sent it.
Frequently Asked Questions
How do I know if my laptop has a virus?
Common signs include your laptop running slowly, programs crashing or freezing, unexpected pop-up ads appearing, your browser home page changing without your permission, or your antivirus program showing alerts. If you see any of these, run a full scan with Windows Defender or your antivirus program right away.
Will removing a virus delete my files?
A full antivirus scan removes the virus but leaves your personal files (documents, photos, music) alone. Quarantine moves the infected file to a safe location where it cannot run, so you do not lose anything. If you choose "Remove" instead of "Quarantine", the infected file is deleted, but that is usually just the virus itself, not your data.
What if the antivirus scan finds nothing but my laptop still acts infected?
Run the scan again in Safe Mode, because some viruses hide from normal scans. If Safe Mode scan finds nothing, the problem might be malware rather than a virus, or your laptop might have a hardware problem. Try running Malwarebytes (a free tool designed for malware) or contact a local computer repair shop for diagnosis.
Can I remove a virus without restarting my laptop?
Most viruses require a restart to fully remove, because they are still running in memory while Windows is open. Always restart when your antivirus program asks you to. If you skip the restart, the virus may not be completely gone.
Is Windows Defender enough, or do I need to buy antivirus software?
Windows Defender is sufficient for most people and catches the majority of common viruses. You only need to buy additional antivirus software if you download files frequently from untrusted sources or if Windows Defender has missed infections in the past. For typical laptop use, Windows Defender is enough.