In that situation it's still up to the Windows Time service when to actually performs a sync, which will be once per week.There is a Special Poll Interval setting under HKEY_LOCAL_MACHINE\SYSTEM\Current Control Set\services\W32Time\Time Providers\Ntp Client (note: it has moved at least once between Windows versions) which is the time (in minutes) between time syncs... While modifying that registry value may update the "next sync time" displayed in the control panel, I have found it does not actually affect how often the clock is synched.I've seen suggestions that you change the existing Synchronize Time scheduled task so that it runs more often. I tried making that task run once a day and my clocks still drifted.Upon investigation, that task simply makes sure the Windows Time service is running and if it's already running the task does nothing.
I have set the time and date correctly in both windows and the BIOS and this normally works fine until I reboot or turn off the computer, I have reason to believe this is caused by the CMOS battery but I can't be sure.
They're typically CR2032's which you can get anywhere Malware: Sometimes malware messes with the data/time to manipulate login data and such.
I'd run some scans with malwarebytes (free) Time Sync: There are a few tricks you can do to try and resync the time.
So why did my Windows XP computer loose five minute?
To check the time synchronization settings on Windows XP, I double-clicked on the clock in my system tray and selected the Internet Time tab on the Date and Time Properties window.