Windows Defender failed to open because Error 0x800704ec

Sometimes, when you try to enable Windows Defender, it is still turned off and shows the following message:

This program is blocked by group policy. For more information, contact your system administrator. (Error code: 0x800704ec)

With this error message, you won’t be able to enable Windows Defender.

This is not really a problem as the software and the operating system have been intentionally designed in this way. The reason for this is that an anti-virus software is currently installed and active on the computer and to avoid conflicting software activities, an antivirus software automatically disables Windows Defender. The following methods provide steps on how to work around this issue.

Không mở được Windows Defender bởi Lỗi 0x800704ec

Method 1: Basic uninstall solution

This issue can be solved by simply uninstalling any antivirus or software program from the computer making Windows Defender act as the system’s only protection software. To do this, follow the steps below.

  1. Hold Windows key and press R
  2. Type appwiz. Cpl and press Enter
  3. Search for the Antivirus program you intend to remove and click on it
  4. Select Uninstall .
  5. Confirm any additional prompts by selecting Yes when the system asks if you are sure you want to uninstall software.
  6. Restart the computer by selecting yes when the system prompts it to restart in order to finish uninstalling the program; Or by pressing Windows Key on your keyboard and then clicking restart from your power options .

If the steps above did not help uninstall anti-virus / spyware or other security programs follow this guide to remove anti-virus

Now your Windows Defender should be up and running. If not, make sure it’s turned on. To make sure it is working, do the following

  1. Press Windows Key
  2. Select Control Panel
  3. Type Windows Defender in the search bar located in the top right corner
  4. Select Windows Defender
  5. Now make sure it’s turned on.

If the above steps didn’t solve the problem, please use method 2 below to fix the problem immediately.

Method 2: Advanced Registry editing solutions

In very few times, method 1 may not solve the problem and this method provides an immediate fix by modifying the registry key to fix the situation. Some users may find this step more complicated, but the steps below have been broken down to make the process as easy as possible.

  1. Hold Windows key and press R
  2. Type regedit. Exe and press Enter. Click Yes if it asks for permission

  3. Double click HKEY_LOCAL_MACHINE (from the left pane)
  4. Double click on Software (from the left pane)
  5. Double-click Policies (from the left pane)
  6. Double click on Microsoft (from the left pane)

  7. Select Windows Defender (from the left pane)
  8. Double-click on the item named Defender from the right pane

  9. Enter the value 0 in the new box that appears
  10. Click OK

  11. Now press Windows Key once
  12. Select Control Panel
  13. Type Windows Defender in the search bar located in the top right corner
  14. Select Windows Defender
  15. Now make sure it’s turned on.

If the steps above don’t solve the problem then give it a try

  1. Follow steps 1-6 above
  2. Double-click Windows Defender
  3. Select DisableAntiSpyware
  4. Double-click the item named Default from the right pane
  5. Enter the value 0 in the new box and press Ok
  6. Now follow steps 11-15 to enable Windows Defender and check if it works

Method 3: Local Group Policy

Sometimes there may be no problem with Windows Defender and the system itself but your Windows Defender can only be turned off from Local Group Policy. You can easily check and change the settings (if it is disabled) from the Group Policy window of Local Group Policy.

  1. Hold Windows key and press R
  2. Type gpedit. Msc and press Enter

  3. Double click on Administrative Templates found under Computer Configuration (from the left pane)
  4. Double click Windows Components (from the left pane)

  5. Click Windows Defender (from the left pane)
  6. Double click Turn off Windows Defender (from the right window)

  7. Make sure it is not enabled . Click on Not Configured and click Apply then select Ok

Now turn on Windows Defender and check if it gives the same error or not.

Method 4: Turn on Windows Defender

If you don’t have other antivirus programs installed on your computer and you can’t turn on Windows Defender then it may be disabled. To enable Windows Defender follow the steps below.

  1. Hold Windows key and press R
  2. Type of services. msc and press Enter
  3. Find Windows Defender and double click on it
  4. Make sure that the Startup type is Automatic (by opening the drop-down menu in the Startup section) and the Windows Defender service is enabled (by clicking the Start button).