Error 1747 : The Authentication Service is Unknown

I had a Windows 7 machine in one of the racks with a bunch of services not starting, no networking so not much of anything since its headless and graphics are network remote, so I pulled it out and switched its graphics cards to see what was going on.

Really slow to boot windows, after login black screen with mouse, sluggish response.
dhcp, lass, service showing ‘starting’ and can’t be stopped or restarted
ping etc gives no network, or various network errors
Event logs stop working with “Error 1747 : The Authentication Service is Unknown”
Even a BSOD on a reboot

sfc /scannow  no issues, fsck, no issues. hardware all looked ok.

As usual MVP advice is reformat and re-install, so sad.  So i did this instead

From admin shell, cmd

netsh winsock reset

and rebooted, totally fine after that. sigh…