There are also anti-malware products made by other companies that you can choose from. Running multiple anti-malware apps at the same time can cause your system to be slow or unstable. If you install an anti-malware app from a different company, Microsoft Defender will automatically turn itself off. If you install two anti-malware apps from other companies, however, they might both try to run at the same time. Don't open email messages from unfamiliar senders, or email attachments that you don't recognize - Many viruses are attached to email messages and will spread as soon as you open the attachment.
It's best not to open any attachment unless it's something you're expecting. For more information see: Protect yourself from phishing.
Use a pop-up blocker with your internet browser - Pop-up windows are small browser windows that appear on top of the website you're viewing. Although most are created by advertisers, they can also contain malicious or unsafe code. A pop-up blocker can prevent some or all of these windows from appearing. The pop-up blocker in Microsoft Edge is turned on by default.
If you're using Microsoft Edge, make sure SmartScreen is turned on - SmartScreen in Microsoft Edge helps protect you from phishing and malware attacks by warning you if a website or download location has been reported as unsafe. For more info, see What is SmartScreen and how can it help protect me? Pay attention to Windows SmartScreen notifications - Be cautious about running unrecognized apps downloaded from the Internet.
Unrecognized apps are more likely to be unsafe. When you download and run an app from the internet, SmartScreen uses info about the app's reputation to warn you if the app isn't well-known and might be malicious.
Keep Windows updated - Periodically, Microsoft releases special security updates that can help protect your PC. These updates can help prevent viruses and other malware attacks by closing possible security holes. Windows Update helps to make sure that your PC receives these updates automatically, but you may still have to restart your machine occasionally for the updates to install completely. Use your internet browser's privacy settings - Some websites might try to use your personal info for targeted advertising, fraud, and identity theft.
All modern browsers have privacy settings that you can enable to control what sites can see or do. For more information about configuring the privacy settings in Microsoft Edge see Configure your privacy settings so they're right for you. UAC can help keep viruses from making unwanted changes. To open UAC, swipe in from the right edge of the screen, and then tap Search. If you're using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then click Search.
Enter uac in the search box, and then tap or click Change User Account Control settings. Make sure that Tamper Protection is turned on - In Windows 10 and 11 we have a feature called Tamper Protection that prevents unauthorized apps from changing your security settings. Many viruses and malware try to disable anti-malware software or other security settings when they're installed in order to evade detection.
See Prevent changes to security settings with Tamper Protection for information on how to confirm that it's turned on. If you use more than one antivirus or antispyware program at the same time, your PC may experience decreased performance, become unstable, or restart unexpectedly. Now, it is time for you to install the latest Windows operating system.
How to perform a Windows update? Here is the guide:. Step 2: Click Check for updates. If there are available updates, install them and restart your PC. After completing Windows updates, the problem of Windows Defender not turning on maybe disappeared. This can be a problem but you are able to fix it simply by changing the group policy.
After these changes are brought into effect, the issue of Windows Defender not working due to the group policy being turned off should be solved, and you can run it to protect your PC. Then, you can change it to fix this issue. Step 3: Find DisableAntiSpyware key. If you start the Windows system in normal start-up operation, there might be many third-party applications running in the background.
These applications can cause software conflicts and interfere with Windows. This method is quite simple and you can do by following these instructions:.
Step 2: In the System Configuration interface, go to the General tab, choose Selective startup and uncheck Load startup items. Now, all of the possible ways to fix Windows Defender not turning on have been shown to you.
If you think these ways are helpful, you can also share them on Twitter to let more people know. Click to tweet. In order to protect your computer against spyware, ransomware, adware, viruses and other threats, you can try another way that is to use MiniTool ShadowMaker to back up your computer.
In addition to backing up your important files as mentioned above , it can help you easily and effectively back up your Windows operating system, disk, and partition.
If your system ever goes wrong, you can use the backup to restore it to a normal state. Additionally, it supports disk cloning , which helps you transfer all the content on a disk to another for the entire disk data backup. For system disk cloning, the cloned drive can be used to boot the PC in case of a system crash.
Are you interested in this backup software? Step 1: Run this free backup software, continue to use the Trial Edition and choose the local backup mode. Step 2: After entering the Backup page, you can see this program will back up your Windows system by default since the system partitions and destination path are chosen.
Of course, you can click the Source and Destination module to decide what you want to back up and where you need to save the image. Next, just click Back up Now button to execute the operation in Manage page.
In addition, you can choose the entire system disk to create a hard drive image. Or go to Tools page to use its Clone Disk feature to perform a disk cloning for backup.
We have shown you solutions to fix the issue of Windows Defender not turning on; just try them one by one. To keep your PC safe, you should use the professional and reliable PC backup software, MiniTool ShadowMaker to back up the important files or Windows system automatically.
If you have any other solution to repair Windows Defender or any question related to MiniTool software, please contact us via [email protected] or leave your idea in the comment part below. Download Shadowmaker. Summary : Is your Windows Defender not turning on? Tip: Sometimes, SFC scan will fail to work with an error message. Note: Installing Windows update may give rise to data loss, thus, you had better back up your important files before an update so that you can restore the computer to a previous state in case of accidents.
Read More. Tip: Windows failed to check for updates? Note: We strongly recommend you to back up Windows registry before modifying it to avoid system accidents. And enter the Services tab to enable all Microsoft services. Tip: In order to protect your PC well, you can take full advantage of its Schedule option to automatically back up your files or the Windows OS. What to do if Windows Defender is not working?
Why my Windows Defender is not updating? The causes for Windows Defender not updating are various, such as connectivity problems, Windows Defender services not running, corrupted system files, a Windows update problem, etc. The solutions should depend on the error message that you have received.
