Definition Update for Windows Defender Antivirus - KB2267602 (Definition 1.263.800.0). This update will not install.

This has been going on for months. Definition Update for Windows Defender Antivirus - KB2267602 (Definition 1.263.800.0) will not install. It keeps trying to do it over and over but it never moves forward. It tries to install every single day but it has never once been successful. I run McAfee Total Protection. I don't need Windows Defender but if I shut it off I get a relentless amount of notifications to turn it on even though I have notifications turned off. I have run the troubleshooter, downloaded a fix from this site, and done several supposed fixes all for nothing. I have no idea what else I can do.

Question Info

Last updated April 18, 2019 Views 6,303 Applies to:
Answer  If you completed the instructions to turn off Windows Defender in the above tutorial and Defender is still working then I suggest you take your computer to a computer technician or reset Windows or do a clean install of Windows 10 and start all over.

Or see if you want to remove Update 1709 and revert to version 1703.

If you prefer to seek direct assistance from MS try

Good luck…

MVP Consumer Security 2014-2016
Windows Insider MVP 2016-2018

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