Block Browser Extensions on Windows

Step 1: Open the Registry Editor

Press the Windows key, type regedit, and press Enter. Click Yes when prompted by User Account Control.

Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\

Important: Back up your registry before making changes. Go to File > Export to create a backup.

Step 2: Block Chrome Extensions

Under the Policies key, create a new key named Google, and inside that, create another key named Chrome.

Inside the Chrome key, create a new key named ExtensionInstallBlocklist.

Inside ExtensionInstallBlocklist, create a new String Value:

• Name: 1
• Value data: *

The wildcard * blocks all extension installations. When users try to install an extension, they will see an error message saying extensions are blocked by the administrator.

Full registry path: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\ExtensionInstallBlocklist

Step 3: Block Microsoft Edge Extensions

Under the Policies key, create a new key named Microsoft, then inside that, create Edge.

Inside the Edge key, create a new key named ExtensionInstallBlocklist.

Inside ExtensionInstallBlocklist, create a new String Value:

• Name: 1
• Value data: *

Full registry path: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge\ExtensionInstallBlocklist

Step 4: Block Firefox Add-ons

Under the Policies key, create a new key named Mozilla, then inside that, create Firefox.

Inside the Firefox key, create a new key named ExtensionSettings.

Inside ExtensionSettings, create a new key named * (asterisk). Inside the * key, create a new String Value:

• Name: installation_mode
• Value data: blocked

Full registry path: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\Firefox\ExtensionSettings\*

Step 5: Remove Administrator Rights

Registry changes alone are not enough if the user has administrator access. Users with admin rights can reverse these changes.

To fully enforce the restriction:

• Change the user's account type from Administrator to Standard User in Settings > Accounts > Family & other users.
• Use a separate administrator account for making system changes.

Step 6: Verify the Changes

No system reboot is required. Open each browser and try to install an extension:

• Chrome: Visit the Chrome Web Store and attempt to add an extension. You should see a message that extensions are blocked.
• Edge: Visit the Edge Add-ons store and attempt to install. The install button should be disabled or show an error.
• Firefox: Visit the Firefox Add-ons page and attempt to install. Firefox should block the installation.