Windows defender encountered an error 0x800703eb

Error code: 0xb4". Your computer has installed some third party protection software which is not compatible with Windows Defender. The conflict between these two tools leads to the error. Registry is missing or corrupted, system drivers are outdated or Windows is not updated. There are cases that computer reports 0xb4 because settings of Windows are lost.

The error stops Windows Defender from working flawlessly and facilitates virus to penetrate. Hence, it should be fixed to assure system a secured environment. A number of solutions can be used to get rid of the error due to causes vary from user to user. This part gives two most commonly recommended solutions. Disable or uninstall third party antivirus temporarily. You can go to software's official site to look for detailed manuals.

Keep Firewall turned on. If you have both third antivirus software and firewall installed on your computer, you should make sure Windows firewall is enabled. Click Start button and type Windows firewall in the search box. Click Windows Firewall from the search result. Start Windows Defender. Click Start button and type Service in search box and right-click Service from search result to run it as administrator. In the Service window, search for Windows Defender and set it as Start.

Restart computer to make these settings take effect. Open Registry Editor. If you are prompted by UAC to give confirmation, click Yes. You'll see a file named DisableAntiSpyware on the right part of the window.

Replace 1 with 0 and click OK. Step 4 Restart computer and Windows Defender will back to normal working status. To many computer users, nothing will be worse than system gets damaged and you have to reinstall it. During that process you have to spend a lot of time to reinstall system and drivers for hardware, download and reinstall programs you often use, reconfigure system settings, reload personal files, etc.

If you don't want to undergo this, you should keep a system backup. It has always been being suggested to create a system image for your computer in case of system problem or crash. The image file should include all data of system partition, such as Windows, system settings, installed programs and files.

The system image is supposed to be stored in a location which is separated from system partition, so that it won't be affected when system goes wrong. Having a system backup image, you can restore system when your system slows down or can't work smoothly.

How to backup windows? Eassos System restore, easy-to-use system backup software , is designed to complete system backup within several clicks of mouse button.

Install Eassos System Restore and its boot options to your computer. Launch the backup software and click Backup button from the main interface. Click "Next" button to start backing up system. Before that you can click "Options" to configure advanced settings, such as where to store the system image, how to compress the image files, set password, etc. If you don't know what to do with these options, you can follow the defaulted settings.

Reason: Antimalware protection has stopped functioning for an unknown reason. In some instances, restarting the service may resolve the problem. Monday, May 6, PM. But you have to copy it offline, if you have a VM, mount the. Wednesday, August 14, AM. Best Regards, Daisy Zhou Please remember to mark the replies as answers if they help.

Tuesday, May 7, AM. Hello, the server is domain-joined. I have backups, but the issue is there for longer period than backups' retention period, so I'd just be restoring to state where the problem already exist Isn't there some debug logging option I could enable and look into?

Hi, Try the following steps: 1. Download and install Process Monitor according to Process Monitor v3. Restart Windows defend service and wait it to stop automatically or report error. From above method, we can try to find which process to deny Windows Defend service running when we restart Windows Defend service. Wednesday, May 8, AM. Hi, If this question has any update or is this issue solved? Also, for the question, is there any other assistance we could provide?

Friday, May 10, AM. Hi, The procmon trace contains a lot of private information, I think it may be inconvenient to upload such information in the forum, we can try to see if there is an error message related to our problem. Or we try to hide private information and upload it as text. The language type or platform for the destination directory and must be the same. Do you wish to continue?

You can only install this update on Service Pack. There is no need to install this update. LOG file. You must reboot for these changes to take effect. At minimum, you must have Service Pack installed. You can choose to replace the High Encryption security file with the updated Standard Encryption security file now. Would you like to Uninstall these hotfixes now? Would you like to overwrite this directory with new Uninstall information? Setup cannot continue.

TXT file was found in your Hotfix directory. TXT file. Would you like to delete it now? Install package must be rebuilt. Failed to install catalog file. To continue with setup, you must accept the agreement. However, this requires significant disk space. Do you want Setup to archive these files? To apply the changes, the wizard has to restart Windows. To restart Windows automatically, click Finish.

To close this wizard, click Finish. The destination directory contains an evaluation copy of Windows. To enable this service, click OK. After Setup is complete, the print spooler will be disabled. The current state of the computer can be archived only on your local computer. Please download and install the latest version of fix. To prevent possible problems, these files will not be installed by the service pack.

Please contact your system administrator or retailer immediately to obtain a valid Product Key. The Service Pack will not be installed. The Service Pack contains updated versions of those files, which work to provide a stable environment for your programs. Enter a shorter name. Make sure the Cryptographic service is running on this computer. Description: Antivirus signature version has been updated.

This event is reported when signatures are successfully updated. Description: Microsoft Defender Antivirus has encountered an error trying to update signatures.

User action: This error occurs when there is a problem updating definitions. To troubleshoot this event: Update definitions and force a rescan directly on the endpoint. Description: Microsoft Defender Antivirus engine version has been updated. This event is reported when the antimalware engine is successfully updated. Description: Microsoft Defender Antivirus has encountered an error trying to update the engine.

User action: The Microsoft Defender Antivirus client update failed. This event occurs when the client fails to update itself. This event is usually due to an interruption in network connectivity during an update. The antimalware engine will attempt to load the last-known good set of definitions. Description: Microsoft Defender Antivirus has encountered an error trying to load signatures and will attempt reverting back to a known-good set of signatures. This error can occur when the client encounters an error while trying to load the definitions, or if the file is corrupt.

Microsoft Defender Antivirus will attempt to revert back to a known-good set of definitions. To troubleshoot this event: Restart the computer and try again. Download the latest definitions from the Microsoft Security Intelligence site.

Note: The size of the definitions file downloaded from the site can exceed 60 MB and should not be used as a long-term solution for updating definitions. The antimalware platform will load the last-known good antimalware engine and attempt to update. Description: Microsoft Defender Antivirus could not load antimalware engine because current platform version is not supported.

Microsoft Defender Antivirus will revert back to the last known-good engine and a platform update will be attempted. Description: Microsoft Defender Antivirus has encountered an error trying to update the platform. Download the latest platform to maintain up-to-date protection. Description: Microsoft Defender Antivirus will soon require a newer platform version to support future versions of the antimalware engine.

Download the latest Microsoft Defender Antivirus platform to maintain the best level of protection available. Description: Microsoft Defender Antivirus used Dynamic Signature Service to retrieve additional signatures to help protect your machine.

User action: No action is necessary. This event is reported when the Dynamic Signature Service successfully deletes out-of-date dynamic definitions. User action: Check your Internet connectivity settings. Description: Microsoft Defender Antivirus downloaded a clean file.

Description: Microsoft Defender Antivirus has encountered an error trying to download a clean file. The Microsoft Defender Antivirus client encountered an error when using the Dynamic Signature Service to download the latest definitions to a specific threat.

This error is likely caused by a network connectivity issue. Description: Microsoft Defender Antivirus downloaded and configured offline antivirus to run on the next reboot. Description: Microsoft Defender Antivirus has encountered an error trying to download and configure offline antivirus. Description: The support for your operating system will expire shortly. Running Microsoft Defender Antivirus on an out of support operating system is not an adequate solution to protect against threats.

You must upgrade the operating system for continued support. Description: The support for your operating system has expired. Microsoft Defender Antivirus is no longer supported on your operating system, has stopped functioning, and is not protecting against malware threats. Reason: The reason Microsoft Defender Antivirus real-time protection has restarted a feature.

User action: You should restart the system then run a full scan because it's possible the system was not protected for some time. The Microsoft Defender Antivirus client's real-time protection feature encountered an error because one of the services failed to start. If it is followed by a event ID, the failure was temporary and the antimalware client recovered from the failure. We recommend running a full system scan when you see this error. It is recommended that you run a full system scan to detect any items that may have been missed while this agent was down.

User action: The real-time protection feature has restarted. If this event happens again, contact Microsoft Technical Support. Description: Microsoft Defender Antivirus real-time protection scanning for malware and other potentially unwanted software was enabled.