How to discard BIOS time completely?

[Mikko]

Hello!

My computer's motherboard started acting up and cannot keep the system
time anymore. The time changes at random intervals severals years
ahead. At first it went 10 years ahead, after holidays the date read
something like 12/26/16520.

I have replaced the CMOS battery and cleared CMOS, but I am not asking
help for the actual issue here. Instead, I am asking if I can keep
Windows 7 from using the incorrect BIOS time.

Now I get the following messages in Event Viewer whenever the time
changes:

Kernel-General
The system time has changed to ‎2020‎-‎12‎-‎20T14:26:28.500000000Z
from ‎2010‎-‎12‎-‎20T14:26:28.815624100Z.

This suggests to me that Windows reads the BIOS time periodically and
adjusts the time to it. Is there a way to disable this behaviour, and
let Windows use the time it got at boot time, and only increase it by
its internal timers? I rarely boot this computer so this would be
completely acceptable for me.

[Nobody]

Post by Mikko
Hello!
My computer's motherboard started acting up and cannot keep the system
time anymore. The time changes at random intervals severals years
ahead. At first it went 10 years ahead, after holidays the date read
something like 12/26/16520.
I have replaced the CMOS battery and cleared CMOS, but I am not asking
help for the actual issue here. Instead, I am asking if I can keep
Windows 7 from using the incorrect BIOS time.
Now I get the following messages in Event Viewer whenever the time
Kernel-General
The system time has changed to ?2020?-?12?-?20T14:26:28.500000000Z
from ?2010?-?12?-?20T14:26:28.815624100Z.
This suggests to me that Windows reads the BIOS time periodically and
adjusts the time to it. Is there a way to disable this behaviour, and
let Windows use the time it got at boot time, and only increase it by
its internal timers? I rarely boot this computer so this would be
completely acceptable for me.

Try starting the computer and go to the BIOS directly, and see the time.
Turn off, and try again, and see if it changes. Do not let Windows boot.
This is to confirm that it's motherboard problem.

I think everyone here would suspect a virus, or a buggy software, perhaps a
calendar software. To find out who is responsible, hook
SetSystemTime/SetLocalTime, and check who is calling these functions.

[Mikko]

Hello!

Post by Nobody
Try starting the computer and go to the BIOS directly, and see the time.
Turn off, and try again, and see if it changes. Do not let Windows boot.
This is to confirm that it's motherboard problem.
I think everyone here would suspect a virus, or a buggy software, perhaps a
calendar software.

It is definitely BIOS. I get CMOS checksum errors at bootup and CMOS
settings are not saved. Also, when I try to change the date and time
in BIOS, they change back (and to random numbers) after a few seconds.

But as mentioned, this is NOT what I am asking here...

So far I have uninstalled the "System CMOS/real time clock" in Device
Manager under System devices. It installs back automatically but I am
hoping the service is inactive before the next reboot. So far the time
has stayd stable for some hours, but I'll keep monitoring.

- Mikko