BIOS clock and windows clock

[rookie1010]

Hello

is the BIOS clock and windows clock, i mean if i change say the windows clock, does the BIOS clock automatically get changed and likewise if i change the windows clock does the BIOS clock change

 

[n00bhead]

If you restart your computer the Windows clock is up-dated according to the BIOS clock,

the BIOS is never up-dated via Windows,

therefore if your CMOS is incorrect due to a BIOS battery fault Windows clock will also be incorrect,

this is in principle of course but who knows.

 

[RicoDirenzo]

YOu are right...you cannot update the Bios form Windows. The Bios is exclusive to the systems BIOS chip, Say Award, you can only update the Bios (CMOS) by bypassing the Windows logon at intitial bot. (F2 or Del key hit)

 

[rookie1010]

so if i change the clock on windows to say 5 october 2004, and then when i restart my machine i
the bios clock will fix the windows clock back to 5 october 2005, correct?

 

[brady]

Edit: Yeah what major said.

 

[TheMajor]

No, it won't. Windows only uses the BIOS time when you install it.

 

[rookie1010]

so after installation of windows the two clocks are independent of each other, no matter how many times one starts windows, correct?

 

[TheMajor]

Yes, I'm pretty sure about that.

 

[rookie1010]

thanks major

 

[n00bhead]

I understood it that if you shut-down Windows then Windows has no possible way of keeping time since it is not in operation,

that in fact this is why you have an independent battery for the BIOS in order for it to keep the time,

it keeps the time and when you boot up Windows, Windows refers to the BIOS clock to get a starting point from,

Windows then takes care of it's clock and it's accuracy from the point it has the power to do so,

if the Windows clock is wrong then it is either a case of the initial time it retrieved from the BIOS being wrong or Windows timekeeping is inaccurate possibily due to short freezes and the like.


I don't know, I have not rebooted to try it out but it made practical sense to me.