Limited Periodic Scanning in Windows 10 to Provide Additional Malware Protection

Every month, Microsoft’s Malicious Software Removal Tool (MSRT) scans more than 500 million Windows devices for malware and malicious software. This tool aids in the detection and removal of malware from 1 to 2 million machines each time, even on those devices running antivirus software. Meanwhile, many Windows customers continue to use the Microsoft Safety Scanner (MSS) to manually scan their PC for malware.

Windows 10 is the most secure operating system Microsoft has ever shipped, and we continue to make it better with regular security updates and new features. For example, we’re making malware detection and protection even easier and more seamless for our customers, whether they choose to use the built-in Windows Defender antivirus or a third-party antivirus solution. Starting with the Windows 10 Anniversary Update this summer—and available in this week’s Windows Insider build—Windows 10 will include a new security setting called Limited Periodic Scanning. Windows Insiders can enable this feature on unmanaged devices today.

When enabled, Windows 10 will use the Windows Defender scanning engine to periodically scan your PC for threats and remediate them.  These periodic scans will utilize Automatic Maintenance—to ensure the system chooses optimal times based on minimal impact to the user, PC performance, and energy efficiency—or customers can schedule these scans. Limited Periodic Scanning is intended to offer an additional line of defense to your existing antivirus program’s real-time protection.


Enabling Windows 10 Limited Periodic Scanning

If you are not using Windows Defender as your antivirus program on Windows 10, you can enable Limited Periodic Scanning under Settings.

  1. Navigate to Settings -> Update & Security -> Windows Defender.
  2. Turn Limited Periodic Scanning on.

Screenshot of the Limited Periodic Scanning option

If you are already using Windows Defender as your antivirus program on Windows 10, then you already have this feature enabled. Windows Defender periodically scans your PC, also known as Scheduled scans.


Notifying you of threats found on your PC

When Windows 10 Limited Periodic Scanning is turned ON, and even if you are NOT using Windows Defender for your real-time protection, the Windows Defender user interface and History tab will allow you to view any additional threats that have been detected.

Screenshot of Windows Defender periodic scanning settings Screenshot of the Windows Defender History settings

When a threat is found, Windows Defender will notify you with a Windows 10 notification. In most cases, Windows Defender will also automatically take action on the threat. Clicking on the notification will open Windows Defender where you can further review the threat that was found and the action that was automatically taken.

Screenshot of the Windows Defender scan notification

Clicking the notification will take you to the Windows Defender main user interface, where additional actions (if required) can be taken and applied.

At this time, Windows 10 Limited Periodic Scanning is intended for consumers. We are evaluating this feature for commercial customers, but Limited Periodic Scanning only applies to unmanaged devices for the Windows 10 Anniversary Update.

Windows 10 is our most secure operating system yet, and we will continue to improve Windows 10 with features like Limited Periodic Scanning. With Windows 10, you can rest assured you’ll always have the latest security protections. To learn more about the security features offered in Windows 10 visit:



Deepak Manohar

Microsoft Malware Protection Center

Comments (84)
  1. If this is such a great feature, you could have enabled a scheduled scan(s) in Security Essentials/Windows Defender a long time ago. You did not have to wait for Windows 10.

    Also…Windows Defender is a bit late in detecting new malware, so perhaps such a scan(s) will not detect any new malware until you get a signature (somehow) for it.



    1. adwbust says:

      This is very true lol. MSE/WD is usually the last to add detection and their generic/proactive detections are weak/ineffective/close to nonexistent. Installmonstr lol? MSE/WD is passive protection, waiting for feedback/telemetry/samples from their monitors. If there’s anything suspicious, it just gets logged and reported. Why not prompt or block it?!

  2. David Roper says:

    I am currently running Windows 10 with Windows Defender. I’m a little disappointed that it didn’t intercept ” win32/Dynamer!ac” before it infected my computer . Now that I have found the Trojan, Windows Defender seems incapable of removing it. Please help!

    1. Micheal Robinson I.T. says:

      Windows Defender from the start I thought was garbage. This is why I use a two other programs that are downloadable for free, one being Avast! free antivirus and the other Melwarebytes Anti-malware. I use both the free versions and have for years, with outstanding results. If one wants to upgrade these, that is possible and add more features of protection. I never rely on only one protection program because there are so many definitions and not everyone has them all and updated soon enough to protect customers.

  3. Vegard says:

    What are the advantagaes to this when the scheduled scans stop as soon as you use the computer anyway.?

  4. William says:

    can you turn this feature on/off via registry key or group policy?

  5. Karl Heinz says:

    Dear Deepak,
    I’ve recently tried to use the Microsoft Safety Scanner (Defender offline scan) but it is useless. The Client version is outdated and also it cannot update the definitions. It does not even allow me to update the definitions. When I create a new Microsoft Safety scanner (via USB or CD) it should have all recent definitions on board, so you can safely scan a computer isolated from the network.

    1. Karl Heinz says:

      Pardon, I refered to the wrong product.

      is the one affected.

  6. Jock says:

    Wait, is that the same Automatic Maintenance window defined by Active Hours? Because Active Hours is a 10-hour joke. I use my computer 18×7. You can have 6 hours.

  7. Dan DeVoe says:

    I have had problems with Defender updates since putting Windows 10 on my machine. I also have Norton Antivirus on my machine. For a time I used group policy to block Defender updates and disabled the Defender services from running. Since entering the insider program I restarted Defender but the update errors continue.

  8. Gilbert Villarreal says:

    I love the windows defender option. I’ve always used it. it’s convenient and I’ve never had any problems with it.

  9. fabiclavi says:

    deberíais dar la opción de traducir estas paginas y blog a otros idiomas como el español, para poder evaluar correctamente los contenidos. porque a veces no consigo entender todo lo que se dice.

  10. jorge says:

    quiero limpieza

  11. bonjour,
    Je ne comprend pas l’anglais, l’anglo-américain.
    Pourrais-je avoir la page en français. SVP… S’il Vous Plait.

  12. eduardo dipascuale says:

    muy bueno el defender scan results .me encontró un malware , que otros antivirus no lo hacían…..bien

  13. chandramohan says:

    Dear Microsoft,
    windows defender is unable to stop Trojan.heuer2.JP.Hu @ ao84. This Trojan affected windows defender updates and other windows updates. Bitdefender removed this Trojan and my pc run normally. Please make windows defender more effective and efficient so that we need not get third party antivirus.

  14. Abdulaziz Al-Malki says:

    it is nice to see it again with more enhancements.
    But would it cause moderate effect on overall system performance or it wouldn’t?

    1. msft-mmpc says:

      Our periodic scans occur during the maintenance window, which ensures that the user is not interrupted and only when the PC is idle.

  15. Marcos Antonio Ferreira says:

    Alguns travam o mouse na hora de clicar,vocês também poderiam trabalhar nisso acontece comigo hackers.

  16. Cysiek says:

    I would like to hide icon on task bar because I’m using another sofware to protect my system…
    Is there any such as option like this?

    1. msft-mmpc says:

      Thanks for the feedback, we’re investigating options.

  17. Zoli says:

    Kaspersky antivirus install end king Kaspersky!!!

  18. Patti says:

    It says I have another virus protection when I do not. How do I find out WHY I can not have it run all the time?

  19. Castielle679 says:

    I currently use McAfee Live Safe. Having Windows Defender as an additional safety check is such a relief. So far, my laptop hasn’t been infected with viruses. Can’t wait to see what’s next.

  20. Thanks To Windows Team

  21. Thank You Microsoft Team

  22. pitsirikos says:


  23. Nikolaos Brusio says:

    Cool. I love the new feature. Thanks Microsoft!!

  24. Peter Wallace says:

    I have tried to enable perodic scanner but it keeps swithcing off. Sometimes it starts to update the definitions then stops and informs me to check intermet settings. But the settings are fine

  25. shau says:

    my windows /10 0nly go so far and then it quits then say error

  26. Nikolaos says:

    A very useful addition to Windows Defender. I use a 3rd party anti-virus but I prefer having a second layer of defense by utilizing a limited version of WD.

  27. R Thompson says:

    Can you help me with ( ) I have uninstalled FireFox and reinstalled it. Still there. Would I have the same issue with Edge? I use Advances System Care Ultimate 9.1 and IObit Malware fighter 4.2 Pro.

    1. Poul says:

      Hello R.,,
      have you tried Adwcleaner? It may help against hijackers.
      K r

  28. how to activate windows defender in my windows 10 laptop..thanks

  29. SURESH DAYAL says:

    Microsoft Scanner and security software and I would be glad if there was software to remove double same download software.

  30. Andrew says:

    It’s useless when another anti-virus software exists in system.

  31. Douglas L Hadley says:

    I like Windows 10.

  32. Charis Lancaster says:

    This periodic scanning is such a cool idea. We all know that a single protection app can not catch everything. Now I know that I basically have a double firewall so to speak. Thank you so much!

  33. A. P. Roy says:

    hey, i install quick heal before windows aniversary update and after install aniversary update it always notify me about windows defender and quick heal are both turned off, but actually quick heal is on. what shoud i do? Please give me solution

  34. Josh says:

    I keep trying to turn Windows Defender on but it says I have another antivirus installed. I do not. You need to give more details so I can find out what program is fooling it and uninstall it.

  35. Dave Lee says:

    Windows Defender won’t turn on as it says that there is another AV program handling protection – well – there isn’t – how can you tell what program Actually is stopping Defender from being turned on? All I get is a list of ALL applications……..I have uninstalled a few that I don’t need anymore – but I can’t uninstall all of my apps.

    1. msft-mmpc says:

      Hi Dave, Josh, and others – open the Start menu and type ‘antivirus’ (or type ‘antivirus’ into the Cortana search box) – the results should show the AV programs you have installed (including Defender).

      1. Bob DeVoe says:

        Windows Defender is turned off because it says I have another AV program running. I do not. When I type antivirus in the start menu only Windows Defender shows up and it says it is turned off. What’s going on?

  36. Earl Hickey says:

    I certainly appreciate the above information, and welcome it’s action. Thanks so very much.

  37. Charalampos Tsoulas says:

    Defender in Full Scan is unbearably TOO slow!!!

  38. rwedunyet says:

    I am so confused!!!! I have been using MSE/WD forever and IObit /ASC and now I am getting phone calls telling me my computer is infected, limited internet, and reimaging scans constantly bothering. WTH help please

  39. Tadeu Fonseca Veloso says:

    Windows 10 is all good. It’s a starting where everything really begins. There will be many important news in the next future, I’m sure.

  40. Biplob Dev says:

    Microsoft, Oracle and SAP holds the superior position on this universe when it comes to any products/services that they deliver. Great thing in business are always done by a group of talented people.

  41. Joshua says:

    Windows defender needs to report exactly what program/task is turning it off. This improvement is greatly needed as it will more easily diagnose why it keeps turning off.

  42. Thank you for the help been having trouples and i dint no that i can have two; Window Defender and my avostiav

    main one thanks again.

  43. Frans du Buy says:

    I had considerable problems with malware and am glad I now have the support of Microsoft defender software. Originally when I first installed windows 10 I had to use Norton Internet Security although it originally did not have data backup capabilities. They then included it. But I am very disappointed with the quality. I tried to use Microsoft defender but failed as Norton blocked it. I wonder why Microsoft did not include backup and Internet Security software with Windows 10. Maybe they were afraid of UNCLE SAM and his big stick. Originally Microsoft Edge browser functioned fairly wel. But during a Norton backup to an external hard drive, there was a power failure, I also had a Polar wrist heart rate device connected to my laptop. This screwed up everything. I had to disable Edge browser and uninstall Norton. Thereafter I could not get Edge to function until this update. I made the mistake to make use of software which was apparently malware with CNET icon near the advertisement.

  44. nathaniel says:

    i need help since the windows 10 anniversary update me and a bunch of others have been having problems with defender i believe a patch is needed i had to download 360 security so i will see how it goes. i also have downloaded the malicous software removal tool. multiple scans from numerous devices show no threats but when defender wont turn on and it says my pc is in danger and periodically shuts down on its own… there is something going on please help me. ERRORS: 0x8050800c and 0x800705b4

  45. PAULINO says:


  46. Robert Bavister says:

    Great as a Eighty year novice at computer work i need all the security and help thats available. Thank you Microsoft.

  47. Sara Shellenbarger says:

    Thank You. Is it free with windows 10

  48. Vít Kristen says:

    Thank You Microsoft Team, amazing !!

  49. Mathew J Kiernan says:


  50. Linda Sharleen Daniel says:

    Since I downloaded Windows 10, I have not been able to print. How can I check to see if the firewall is blocking my printer?

  51. joel says:

    when a antivirus is preventing defender from running please show the program in question

  52. Mary says:

    I like the idea. My question is “does it automatically download updated viral definitions, oe must this be done manually?

  53. Leonard Kammer says:

    I turn it on and then check in a few days and it has been turned off.

  54. gillesforget says:


  55. Gerald Berger says:

    I would gladly add exceptions for directories before I activate Windows Defender but I can’t because I already have another antivirus installed. To add exceptions it seems I’d have to uninstall my main antivirus and install it again after adding the exceptions. That’s silly.

  56. Robert Carr says:

    Hello, I am trying to download and install CyberLinkPD11_2110_GM2_Trial_VDE120809-01 and I keep being denied with this app has been blocked for your protection. What can I do?

  57. WHY DO YOU CARE? says:

    Nice job. My anti-virus software asked me to restart. So I restarted. Now it asks me to use windows defender to scan products and I can’t open my anti-virus software that ACTUALLY GETS RID OF VIRUSES.

    No better than Sony.

  58. yarmouk says:

    i deleted the lost AV and everything belong to it but until now i can’t turn on the real time protection can you help me guys ?

  59. Eduardo Silva says:

    “Fico muito grato pela agilidade do programa, sempre minucioso e atento. Não deixa passar nada despercebido. Obrigado.”

  60. Albert Dorrington says:

    I’m not sure what’s going on here, but I presume you are doing a good job.

  61. Jan Goodman says:

    I have a Win service.exe and Win-Soft.exe on my computer that’s giving me a fit. I cannot get them off. One of them periodically freezes my computer with fake scam about calling a no. for help. It says its Microsoft which I know it is not. Help! Ive used spybot and malwarebites to no avail.

  62. William Cox says:

    I truly am grateful for Windows Defender Security. I believe it will protect us all from unwanted threats and malicious people
    who are not for the right thing. I welcome the protection and security which allows me the freedom to complete my daily tasks.
    Thank’s Microsoft,
    Wm D. Cox

  63. Je suis très contemp

  64. Christopher C. Woodbury says:

    Having Windows 10 turn off Windows Defender real-time protection because I have installed MalwareByte Anti-Malware is just stupid. I am running the free version which DOES NOT provide real-time protection. It is there to as backstop to Windows Defender. Assuming Windows Defender will find every bit of malware is also just stupid. I scan my systems periodically with MalwareBytes Anti-malware, Safer-Networking’s Spybot, and I use ClamAV’s engine to scan memory through ClamWin. I may install AVG, too. DO NOT, DO NOT, DO NOT turn off Windows Defender just because there is another anti-virus on my system. It is inappropriate on your part. I make that decision which anti-virus system is doing real-time protection NOT YOU.

  65. Kjetil Utne says:

    I am not able to activate Windows Defender, since it says that another AV program is active. However, that is not the case, I have no other programs. Please identify a solution to this.

  66. TINA says:


  67. Chen Jun says:

    I like that anti-virus . tks .wait a moument.i will update the AV software.

  68. abe rolnick says:

    I bought this windows 10, Dell 64 bit computer less than 6 months ago. If DEfender was so good why did I get infected with mal ware and multiple viruses?
    I had to buy a dedicated third part OC diagnostics software tool to clean up my laptop

  69. H.-D. Dettmer says:

    I have Kaskpersky on my Desktop. Kaspersky switch Defender off. Now I am concerned that my computer is not defended enough. What is your proposal?
    Best regards

  70. Odin Jensen says:

    Windows will not let me activate realtime protection from Defender. It says the pc has another antivirus program protecting it, but I already uninstalled AVG to see if this was the culprit making the system slow and irresponsive. What to do?

  71. RMc says:

    TY for Limited Periodic Scanning 😉 I still wish WD had a simple Scan Scheduler like Security Essentials always had? 🙁

    I Like to be able to Schedule a Full Deep Scan for at least once a month.

  72. Tom says:

    I started to activate limited periodic scanning when Trend Micro WFBS is installed. But all devices I did that, after reboot and user logs on, it shows Defender deactivated. As an administrator I enabled it several times again, but keeps on start up on user deactivated.

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