Hi , I did go to Microsoft downloads and did virus scans on the computer & a few other of their free tools they offer and after that I re-booted. Windows Defender came right back on , much to my surprise ! Give that a shot !
Windows Defender in Windows 8.1 Will Not Turn On
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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
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Anonymous
2015-09-14T20:40:39+00:00 -
Anonymous
2015-09-14T19:15:30+00:00 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?
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Anonymous
2015-09-10T00:18:10+00:00 No it didn't work for me