Xuan wrote:
> I observed an error sign on "microcode update device" in the device manager
> window under system devices. I first tried to disable/enable the device to
> fix the problem, but it didn't work. I then uninstalled the device thinking I
> can reinstall it to fix the problem. After uninstallation, the "microcode
> update device" icon disappeared. [REF.: Windows XP version 5.1 (build
> 2600.xpsp_sp2_gdr.070227-2254 : service pack 2)].
>
> How can I reinstall the "microcode update device"? I'd really appreciate a
> response from you. It seems I only need to reinstall a driver, but I can't
> find it anywhere (including Microsoft download center).
>
> Many thanks!
First of all, don't panic.
Microcode is used to patch the processor. On an Intel P4 processor, this involves
a tiny (2KB) chunk of data. The motherboard BIOS contains a series of these
2KB files, each one named for a particular family code of processor. The
microcode updates also have a version number. The 2KB chunk of data has
a checksum of some kind (not stated), and that is how the processor is able
to distinguish between good and bad chunks of data.
Normally, your BIOS will look through its collection of microcode files,
and try to load one or more. It stops when the chunk of data is accepted.
If the BIOS fails to get any of its microcode patches to match, the BIOS
screen may give a warning message that no microcode was loaded. I don't
remember the exact text of that error.
When the operating system is booted, you can check if a microcode is loaded,
by using the Intel Processor Identification Utility:
http://downloadcenter.intel.com/detail_desc.aspx?agr=n&productid=1881&dwnldid=7838
If you install that program and run it, then go to the "CPUID" tab, it gives
the necessary info. For example, my processor reads out as:
CPU Type 0
CPU Family F
CPU Model 2
CPU Stepping 9
CPU Revision 17
That means my processor is a 0x0F29 (hexidecimal) processor, using the 17th
(integer) revision of the microcode. Now, since I'm using Win2K, there is no
"Microcode Update Device", and the only way the revision 17 got there, is
because the BIOS loaded the microcode patch.
If the microcode was completely unpatched, the "Revision" reads 0.
Now, on some Windows OSes, the Microcode Update Device exists. I don't know
exactly how its installation is triggered. For example, for some entries in
Device Manager, if you go into Safe Mode and delete the device entry from
Device Manager, the device is rediscovered on the next boot, a new driver
is loaded for it, and the Device Manager is thus refreshed. What I cannot
tell you, in this case, is whether that mechanism applies to the Microcode
Update Device or not.
The Microcode Update Device performs a redundant service, in the sense that,
it will load a new 2KB microcode into the processor, if Windows has a
revision which is more recent than the one the BIOS installed. For example,
say that WinXP has 0x0F29 revision 19 available. The Microcode Update
Device would load that on top of the revision 17 already there. Running the
Intel Processor Identification Utility, would then report revision 19.
In other words, the "CPU Revision" is in fact a record of the microcode
file revision that has been installed.
According to this, an "error code" from the Microcode Update Device is "normal".
http://www.kellys-korner-xp.com/win_xp_dm.htm
-->
http://support.microsoft.com/kb/q288302/
"SUMMARY
The Microcode Update device is an interface between the operating system
and an Intel processor based on the x86 architecture. This device provides
the latest microcode updates for the processor if the BIOS does not already
contain this information.
MORE INFORMATION
If the computer that you are using does not contain the processor described
in the "Summary" section of this article, or if your BIOS is up to date with
Intel's latest microcode, the Microcode Update device is not initiated; the
device is unloaded to free up resources. Device Manager marks the device with
a code 24 status message:
The device is not present, is not working properly,
or does not have all its drivers installed.
If the microcode on your computer is current, the drivers are unloaded by
design. In this case, the code 24 status message is expected, and it does
not indicate a problem. The device is marked as hidden and is not visible by
default. Therefore, when the code 24 status message occurs, the message is
not displayed when you are using the default configuration."
It took me a while to find a reference to it, but the driver file is "update.sys".
It was mentioned here.
http://cquirke.mvps.org/sp2intel.htm
There is a reference to update.sys here. It is in a section labeled "plug and
play system drivers", but it is unclear where this might be in a normal
WinXP system.
http://www.911cd.net/forums//index.php?s=&showtopic=7947&st=20&p=46665&#entry46665
;Microcode Update
;Textmode setup copies this file on Intel platforms
;@i:CopyFiles=@update.sys=4
Since I'm using Win2K, I cannot help further. Someone running WinXP should be
able to trace down whether there is a registry entry that controls this,
or what INF it is in etc.
So, my message to you is:
1) The function is redundant. The BIOS does the same operation for you.
If your BIOS is reasonably up to date, there is nothing to worry about.
2) To check whether the BIOS installed an update, use Intel PIU utility.
I don't expect any download is going to just install update.sys for you,
and set up the registry accordingly, so it starts properly.
Sorry I cannot help further,
Paul
