An Error Occurred While Windows Was Synchronizing With time.windows.com? Fix Time Sync
You click Sync now and Windows reports “An error occurred while Windows was synchronizing with time.windows.com.”
Why: the NTP (time) client sent a request but got no usable reply — usually the Windows Time service is stopped, UDP port 123 is blocked, or the w32time service is misconfigured. The fixes below go fastest-first.
Fix 1: Force a resync from Settings
- Open Settings > Time & language > Date & time.
- Turn Set time automatically off, wait a few seconds, then turn it back On.
- Click Sync now. If it succeeds, the time updates and the “Last successful time synchronization” line refreshes.
Fix 2: Restart the Windows Time service and resync from the command line
Open Command Prompt as administrator (Start > type cmd > Run as administrator) and run:
net stop w32time
net start w32time
w32tm /resyncw32tm /resync tells Windows to sync immediately. If it returns “no time data was available,” continue to Fix 3.
Fix 3: Re-register the Windows Time service
If the service is corrupted or its registry settings are wrong, unregister and re-register it. In the same administrator Command Prompt:
net stop w32time
w32tm /unregister
w32tm /register
net start w32time
w32tm /resync /forceThen reboot and click Sync now again. While you’re here, confirm the service is set to start automatically: Win + R > services.msc > Windows Time > set Startup type = Automatic and Start it.
Fix 4: Rule out a blocked port or bad time server
If it still fails, UDP port 123 may be blocked by a firewall, or the time server may be unreachable. Temporarily switch servers: open Control Panel > Clock and Region > Date and Time > Internet Time > Change settings, pick time.nist.gov from the list, and click Update now. If that works, the original server or your firewall was the problem.
FAQ
What does w32tm /resync do? It forces the Windows Time service to contact its time source and update the clock right away, instead of waiting for the next scheduled sync.
The error only happens after a Windows update. Re-registering the service (Fix 3) clears stale w32time registry values that an update can leave behind.
“The computer did not resync because no time data was available.” That means no NTP reply came back — work through Fix 3 (re-register) and Fix 4 (port 123 / server).