This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
I recently updated Windows 8 to Windows 8.1. Windows Defender had been on in Windows 8 and even after the update to 8.1. I turned it off momentarily but have been unable to turn it back on. To my knowledge, I have no other anti-virus programs running. How can I turn it back on?
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
You should have tried to use the Uninstaller in program files. Mine worked that way then I went into the registry to delete all folders I could find on Norton. Also try using this software to uninstall. Advanced system care. They have an uninstaller but download Advanced system care it comes with the uninstaller.
This uninstaller has a registry scan tool that deletes the files of that program in the registry.
http://support.microsoft.com/kb/2563254
See the following compliments of quietman7 MS MVP: **Why you should not use Registry Cleaners and Optimization Tools**
I get a 577 error code
Hi,
I think it's because the service is now under action centre. windows 8.1
Go to windows action centre (just search in the new windows start menu)
Enable spyware/firewall protection.
That s it. I assume this will help you
Rajeev
You have to go to the action center in control panel
control panel > action center > windows defender
you will have an option there to turn it back on.
