Windows regularly changes the time by one minute: what can I do?
Hi all, How to prevent Windows from updating the time? (please read all the text) My windows application developed in for Windows 7/10 & 11, works 7 days a week on a PC that is not connected to the Internet, there is no time server connected to the computer. I developed my application to receive the WM_TIMECHANGE message that is why I notice that I receive this message regularly, at a frequency that seems to depend on the PCs but always with the same offset: 1 minute. My explanation (supposition) would be that Windows maintains a software clock that would shift over time and would update itself when the shift reaches one minute, at least that's what I conclude. Note that this PC is not connected to the Internet and is not on a network. In the event manager, I can find this information in the System item (source=Kernel-General) with the following message: System time changed from 2023-02-08T21:38:00,887702300Z to 2023-02-08T21:39:01.50000000Z. Reason for change: System time synchronized with the hardware clock. Procedure: "" (PID4) This phenomenon that sometimes happens once every 2/3 months, and sometimes every week. This is a big problem for me because I store data as it happens and I timestamp it. How to avoid this automatic clock updating ? - I stopped w32time and even disabled it (w32tm /unregister and net stop w32time) - I've disabled the time synchronisation task in the task scheduler. - I also disabled "Hyper-V Time Synchronisation Service" Nothing helps, Windows changes the time by one minute every ten days or so. Thank you for your help.