Automatic update is from NIST, perfectly legal and the response is blocked. Resolve Host: time-a.nist.gov IP Address: 220.127.116.11 NetRange: 18.104.22.168 - 22.214.171.124 CIDR: 126.96.36.199/16 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: 188.8.131.52 NetRange: 184.108.40.206 - 220.127.116.11 CIDR: 18.104.22.168/24 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.