The windows defender on my PC could not be turned on. It was giving error 577. I uninstalled antivirus on my PC and presto I could turn on the defender. thus the other ntivirus was interfering with the working of the defender.
Windows Defender in Windows 8.1 Will Not Turn On
![](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)
Anonymous
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?
Windows for home | Previous Windows versions | Security and privacy
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.
165 answers
Sort by: Most helpful
-
Deleted
This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Comments have been turned off. Learn more
-
Anonymous
2015-03-27T23:36:09+00:00 -
Anonymous
2015-03-03T23:19:36+00:00 I wasn't replying to a post of yours.
-
Anonymous
2015-03-03T22:03:31+00:00 Sorry, I have been commenting on this thread and as I am following it I am allowed to comment.
-
Anonymous
2015-03-03T21:20:57+00:00 See...
• HOW TO begin your own, new thread about your computer & problem
http://answers.microsoft.com/en-us/page/faq#faqAskQuestion1
• Suggestions for asking a question in help forums