How do I re-enable the VM IC Time Synchronization Provider for a VM?


  • Due to some time synchronization issues, I messed a bit too much with my Time Service settings and now my VM is stuck on the "Local CMOS Clock" time source.

    I would like to get it back to sync with the "VM IC Time Synchronization Provider".

    So far, I tried the solution proposed here: But the VM is still using the wrong source. I also re-installed the Hyper-V Integration package to no avail.

    In the registry, I noticed the key HKLM\SYSTEM\CurrentControlSet\services\w32time\TimeProviders\VMICTimeProvider\Parameters is missing the sub-key "IPC", which exists on another machine that is working as intended.

    Thursday, July 19, 2012 5:33 PM


All replies

  • Hi,

    I'm not sure if ths help. Please refer to and see if that solve your issue.

    Lai (My blog:-

    Friday, July 20, 2012 2:31 AM
  • That's not what I'm trying to achieve. I want to make sure my VM guest synchronizes its time with the host again.
    Friday, July 20, 2012 9:42 AM
  • Hi,

    I have tested and remove

    a) entire VMICTimeProvider - but still able to sync

    b) IPC - still able to sync. & auto regenerate after restart. So not related to the missing registry key.

    My VM (non dc) is also showing "Local CMOS Clock".

    May i know what is roles of the VM?  If this is a domain controller, then to get VM IC Time Synchronization Provider, you need to check Time synchronization in the Hyper-V Manager | Integration Component and restart Windows Time services several times.

    Related post which may/may not help:-

    I'm sorry if above article is not suitable to help.

    Lai (My blog:-

    Friday, July 20, 2012 3:20 PM
  • The VM in question is a DC. The time synchronization feature is enabled in the Hyper-V Manager. I restarted the w32time service numerous times, it's still showing Local CMOS Clock as the time source.

    I'm aware of all 3 of those links. In fact, these operations are what lead to the current state.

    There was an issue with time synchronization (which, as it turned out, was a connectivity issue) so I changed the configuration. After realizing the root cause of the problems, I decided to sync my Hyper-V host system with an external time source and just let the VM guests inherit the time (and then distribute it to all domain members).

    All other VM guests are using the correct time source, except this single DC.

    Friday, July 20, 2012 4:54 PM
  • Oliver , I have done exactly the same as you , only difference is the initial cause in your case a network issue. Did you ever find a resolution to this problem ? Any pointers gratefully accepted and appreciated .


    • Edited by WeeToe Wednesday, August 08, 2012 5:52 PM
    Wednesday, August 08, 2012 5:52 PM
  • Well, I was never able to solve it really. I realized that what I was doing wasn't the right idea in the first place.

    I got an answer on Server Fault:

    Maybe it will help you as well.


    Wednesday, August 08, 2012 8:43 PM
  • Hello,

    Got the same problem this morning.

    For me the solution was to issue the following command on each impacted VM :

    w32tm /config /syncfromflags:DomHier /update

    Only one was not OK, I had to uncheck/check the option under Hyper-v.

    Hope it helps.

    • Proposed as answer by swirch Tuesday, March 04, 2014 6:25 PM
    Monday, September 10, 2012 9:33 AM
  • you're awesome!

    I issued net stop w32tm, w32tm /unregister, w32tm /register (rebuilds the registry entries), net start w32tm

    Shut the vm down.  Unchecked the Time check box, powered up, stuck on the cmos clock.

    I shut down, unchecked the box, powered up, verified still on CMOS.  Shutdown, checked it again, on power up I'm back on VM IC Time Synchronization!

    Tuesday, March 04, 2014 6:25 PM