How to get rid of a computer virus

Is your computer running more slowly than usual? Does it stop responding or freeze often? It might have a virus.

If you can connect to the Internet

These instructions are different depending on which operating system you’re using.

Check your operating system

Windows 8

If your computer is running Windows 8, you can use the built-in Windows Defender to get rid of the virus or other malware.

Windows 7, Windows Vista, Windows XP

If your computer is running Windows 7, Windows Vista, or Windows XP, do the following:

  • Run the Microsoft Safety Scanner. The scanner can be used with any kind of antivirus software (not just antivirus software from Microsoft).
  • Download Microsoft Security Essentials for free. (Note: Some viruses will prevent you from downloading Microsoft Security Essentials.)

If you can’t connect to the Internet

Windows Defender Offline works with Windows 8, Windows 7, Windows Vista, and Windows XP.

Use another computer to download Windows Defender Offline and create a CD, DVD, or USB flash drive.

Windows Defender (built in to Windows 8), Microsoft Security Essentials, and other antivirus software use the Internet to download the latest updates to fight new malware. Windows Defender Offline helps protect against advanced malware that can’t always be detected by antivirus software.

Learn how to use Windows Defender Offline

Learn more

Security researchers: Get paid to thwart cybercriminals. We want your help fighting potential viruses. Microsoft has announced three new bounty programs that offer cash payments in exchange for reporting certain vulnerabilities in and techniques for exploiting Internet Explorer, Windows, and other Microsoft programs. Visit for details.

About the Author
Eve Blakemore

Group Manager, Trustworthy Computing

Eve Blakemore is a Group Manager for Trustworthy Computing who delivers consumer guidance around the latest trends in security and privacy. Eve joined Microsoft in 1998 and has worked in corporate and field roles with Microsoft Learning, US Public Sector, Read more »

Join the conversation

  1. Anonymous

    I have Windows 8. I went to and got a virus from Bing Bar that Defender did not stop. Why is Bing giving me virus? Is it becuase I got Windows 8 that has no start menu and now everything is broken?

    Can I install Windows XP since I never got a virus with Windows Xp. It was a safer and better system than Windows 8.

    Please remove the virus from so that others fo not get it.

  2. Anonymous

    I keep getting pop ups telling me that my virus protection is switched off but no advice on how to turn it back on,

    ? How can I do this ?

  3. Anonymous

    as I was downloading music I got this "moneypack" scam virus with an FBI warning as a front page ,no windos defender or security essentials detects or removes this resiliant anoyance even after downloading the latest definitions from microsoft what is the solution?

  4. Anonymous

    Roberto, my father-in-law had a similar scam virus. We used Malwarebytes' Anti-Virus to remove it. You'll probably need another computer to download it, and you'll need to create a bootable disk if the bogus FBI warning is preventing you from getting into Windows. The reason Windows Defender or Security Essentials didn't stop this virus is because you clicked and gave permission, thinking you were downloading something else. Any time you click and give permission, there's not a lot an anti-virus can do for you.

  5. Anonymous

    I tried above solutions and they did not work.  I have used MSE for ages and it has been compromised – for several days I got a pop up telling me it was turned off and I kept hitting the button to turn it back on – now it seems to have been completely deleted from my system.  Searches for it turn up no program.  When I try to download and reinstall MSE I get error code 0x80070643.  Windows automatic updates for security updates constantly get 8000FFFF errors.  I tried running Microsoft Safety Scanner and it turns up no problem.  There is a Trojan &/or virus on my computer but I can't locate it and it is causing havoc in many of my programs on a random basis but consistently in MS Outlook and Internet Explorer.  About at my wits end…

  6. Anonymous

    See if you have a Windows System Restore Point prior to when these infections became apparent and, if so, try restoring to that point (it will not impact any data on your PC and, unless you are in Safe Mode, is completely reversible). The big box geeks and others would charge you for this advise, but I feel sorry for your predicament. If you are in the Portland, Oregon area, feel free to contact me.

  7. Anonymous

    How do you create a bootable disk with security essentials on it

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