Joe wrote:I'm exploring now, if uninstalling all previous (WUA) hotfixes works there.
Was successful on existing installations:
1. Made a backup of C:\Windows\SoftwareDistribution to not lose Update History.
2. Uninstalled all previously installed Windows Update Client hotfixes (simply uninstalled all non-security hotfixes post-2014, which were mostly installed by recent versions WSUSOU) including KB3102810 (which I installed myself previously trying to fix WU, but was superseded anyway).
3. Got rid of Microsoft Update by removing the checkbox from WU settings (I don't need it anyway).
4. Verified that Windows Update Client was reset to version 7.6.7600.320 from 2014 by checking wuauclt.exe file properties.
5. Installed KB3102810.
6. Restored C:\Windows\SoftwareDistribution from backup to get Update History back.
7. Ran another Windows Update search on the existing installations, which took about 1-7 hours depending on machine specs.
8. Be cautious and review all "Important Updates" before installing anything, because it wants to install some of broken Windows Update Client versions again.
All further Windows Update searches now take from about 5 minutes on a Atom N270 machine to below 1 minute on modern Skylake machine without the KB3172605 rollup
, instead of 10+ hours of 100 % CPU load every day. That's good enough. I'm now looking into how to prevent WSOU from installing any non-security hotfixes. I don't want them.