Automatic update is from NIST, perfectly legal and the response is blocked. Resolve Host: time-a.nist.gov IP Address: 18.104.22.168 NetRange: 22.214.171.124 - 126.96.36.199 CIDR: 188.8.131.52/16 Then I enabled (!!) logging of svchost, went manual and tried another NIST I have in the list. That got blocked and failed as well. Resolve Host: time.nist.gov IP Address: 184.108.40.206 NetRange: 220.127.116.11 - 18.104.22.168 CIDR: 22.214.171.124/24 Finally, starting with U+12 I used windows time server, time.windows.com. That updated just fine. Not sure what the ending blocks are about.