New
#90
After installing McAfee Internet Protection after upgrading to Windows 10, I kept getting:
There were problems installing updates ...
Definition Update For Windows Defender - KB2267602 (Definition 1.221.302.0 - Error 0x80070643
in Windows Update. Uninstalling McAfee, rebooting, using Method 1 in this thread, and then reinstalling McAfee seems to have fixed the problem.
McAfee support claims (probably correctly) that this is not an issue with McAfee, so it seems to be a bug in Windows 10 that even Windows Update tries and fails to install definition updates when a 3rd party A/V software is installed.