Clock has gone slow

Discussion in 'Windows Vista Security' started by spud, Jan 31, 2009.

  1. spud

    spud Guest

    Desktop 6 months old and time gone haywire today.Updated it a number of
    times but keeps going slow>

    Cmos battery??
    spud, Jan 31, 2009
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  2. There's no way to answer that for sure without more info from you.

    Before anyone whose clock is running slow rushes out to buy a new
    battery, he should first take note of whether he is losing time while
    the computer is running or while it's powered off. If it's while
    powered off, the problem *is* very likely the battery. But if it's
    while running, it can *not* be the battery, because the battery isn't
    used while the computer is running.

    If the clock loses time while running, try this:

    Open a command prompt window (Start | Run | cmd) and enter the
    following commands:

    net stop w32time
    w32tm /unregister
    w32tm /register
    net start w32time
    Ken Blake, MVP, Feb 1, 2009
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  3. Actually the battery only is used when the computer is powered off and
    disconnected from the mains (unless the technology has changed over the

    There is always power to the M/B (a trickle charge so to speak) when the
    computer is plugged in. Notice that there are LED's on the M/B that are
    powered on at all times - even when the computer is turned off.

    If there is power to the M/B the battery is not used.

    If I am wrong, please correct me. (-:
    Richard Urban, Feb 1, 2009
  4. spud

    DDW Guest

    That's the way I've always understood it.

    But folks persist in saying a failing CMOS battery is what causes
    Windows time to run slowly.

    That is NOT the reason.

    DDW, Feb 1, 2009

  5. Yes, that's correct, at least for the great majority of computers.

    My understanding is that the trickle charge is insufficient to keep
    the clock running correctly. If the computer is powered off, even if
    still plugged in, the clock primarily runs off the battery, and if the
    battery fails, the clock loses time.
    Ken Blake, MVP, Feb 1, 2009
  6. spud

    Sam Hobbs Guest

    The original AT style power supplies did not provide power when they were
    turned off. Actually the ATX power supplies can be turned off except the
    switch is in the power supply itself, not the front of the computer;

    So those of us familiar with the older technology might tend to think that
    turning off the power would require use of the battery, but computer people
    just have to make things more complicated.
    Sam Hobbs, Feb 1, 2009
  7. spud

    Peter Foldes Guest


    The time is always dependent on the CMOS battery. It runs on that computer open or


    Please Reply to Newsgroup for the benefit of others
    Requests for assistance by email can not and will not be acknowledged.

    Peter Foldes, Feb 1, 2009
  8. spud

    DDW Guest

    No. Time is independent of the CMOS clock/battery when Windows is

    DDW, Feb 2, 2009
  9. I can physically remove the battery (and have done so for an extended test
    of 48 hours) and my desktop tower retains correct time.


    Richard Urban
    Microsoft MVP
    Windows Desktop Experience

    Richard Urban, Feb 2, 2009
  10. spud

    DDW Guest

    As it should.

    Here is a long article about Windows timekeeping.

    Toward the end is a general discussion (Tale of Two Clocks) that
    should show any rational person why the CMOS battery and clock is not
    the reason for time being lost when Windows is running.

    DDW, Feb 2, 2009

  11. Is that 48 hours while the computer is running or not running?
    Ken Blake, MVP, Feb 2, 2009
  12. spud

    DDW Guest


    We're talking about Windows time.

    DDW, Feb 2, 2009
  13. spud

    Dave Warren Guest

    In message <> DDW
    If the computer is running then the battery isn't used even for the CMOS

    In most cases, if the computer is plugged in the 5V standby current runs
    the clock, so the battery is only relevant when the computer is
    completely unplugged or the power supply switch is off.
    Dave Warren, Feb 2, 2009
  14. spud

    DDW Guest

    I believe that's already been established in prior posts.

    But... maybe one more will help shut down the folks who reflexively
    suggest changing the CMOS battery to fix Windows losing time while
    it's running.

    Maybe. They're a thick-skulled bunch.

    DDW, Feb 2, 2009
  15. spud

    Dave Warren Guest

    In message <> DDW
    Gah, yeah. I meant to attach my reply elsewhere in the thread.
    And that's why.
    Dave Warren, Feb 3, 2009
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