dell oem software downloadsSound card problem

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I have an old, but almost "as new condition" Dell Latitude C840 (Pentium 4) laptop computer that I initially bought as a repair job (damaged screen)..

The computer works flawlessly from start-up and will do so all-day, every-day, unless that is, I have to power off and restart, as you would after installing Windows updates etc.

Upon restarting the computer, there is no sound other than the internal speaker 'beeps'..

On opening "Device Manager" I see a yellow (!) icon on the "Crystal WDM Audio Codec" component in "Sound, video and game controllers"... I can find no conflicts, and no reason for the audio to fail to initialise.. Nonetheless, Windows says that the device cannot start because no driver has been installed.. Which leaves me baffled because the driver is installed, and was working just ten minutes before.!

If I manually reinstall thdell oem software downloadse driver everything is fine again until I next need to perform a restart.. Even more baffling, if I turn off the computer and leave it overnight, or even just for an hour, before starting it up again, everything works perfectly and just as it should..

Short of trying a new sound card (which I would need to buy) I'm at a loss as to how to trace or cure the problem.. I already updated the system BIOS from version A08 to A13, but this has had no effect.

Is it likely to be a software issue, or is likely to be faulty hardware.?

The computer is..
Dell Latitude C840,

The BIOS is..
version A13

The Operating System is..
Windows XP Pro - Dell OEM Release, updated to SP-3

The soundcard is..
Cirrus Logic - Crystal Audio WDM

The soundcard driver is..
The latest version, download from the Dell website "/drivers and downloads.."

The problem has existed since the first dell oem software downloadsday I setup and installed Windows, and was present before installing any application software.. All indications are that it is an issue with either the computer hardware, or with Windows/Cirrus Logic drivers (or possibly a conflict between the two.?)

Any ideas.? - Anybody.?
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Hi GM :)

Sounds like the sound card hardware is ok. For some reason Windows is losing the drivers for the sound card. Maybe the bios battery is failing? Windows would lose many of its' settings if the backup battery is dead.

Many it can re-configure during boot up, so would not be noticeable.

The battery is sometimes replaceable, but sometimes soldered in. Do you have a motherboard manual? You could also email Dell for their advice

Best of luck, and happy new year :)
boot a live linux cd and then you will know if it is hardware or windows