Windows Update Log



The Windows Update Log



How To Read The Windows Update Log

By default, Windows Update/Automatic Updates keep a record of all activity/transactions in a dedicated log file at the following location:


If you ever receive an error message on the Microsoft Windows Update Web site or from the Automatic Updates service, you can use the information that is included in the Windowsupdate.log log file to troubleshoot the issue.

This even can be of help when Windows Updates FAIL but no error message seems to be present.

How Do I View/Read the Windowsupdate.log File

To view Windowsupdate.log file, follow these steps:

Windows XP users:

1. Click Start, and then click Run.

2. In the Open box, type %windir%\windowsupdate.log, and then click OK.

The file will now open for viewing in Notepad.

Windows Vista users:

1. Click Start, and in the Search Box type %windir%\windowsupdate.log, and then hit the ENTER key on your keyboard.

The file will now open for viewing in Notepad.


The Windows Update Log Explained:

The following is a very simple guide to what happens during a Windows Update session:

When Windows Update/Automatic Updates starts "Logging initialized" is the first thing to happen.

Then "Service startup" occurs where the following are recorded:

The client version
The directory that is being used
The access type
The default proxy
The current network state you may have an entry that look like:


WU client version 7.0.6000.381
Base directory: C:\Windows\SoftwareDistribution
Access type: No proxy
Network state: Connected


Then the Windows Update Agent is initialized and report of your Operating System etc. is made. you may have an entry that look like:


OS Version = 6.0.6000.0.0.66304
OS Product Type = 0x00000002
Computer Brand = Dell Inc
Computer Model = Dimension C521
Bios Revision = 1.1.6
Bios Name = )Phoenix - Award WorkstationBIOS v6.00PG
Bios Release Date = 2007-04-07T00:00:00


The Setup component also checks the installed version of the Windows Update client to see if the Windows Update client must be updated on your PC.

Now Windows Update/Automatic Updates will look at your PC and see if any updates are missing from the current list of available updates at 


Locating Windows Update Failures

If you receive an error message on the Windows Update Web site, or you notice that some Windows Updates are marked as "Failed" in the computers Windows Update History panel.

Follow these steps:

1. Open the Windowsupdate.log log file in Notepad.

2. On the Edit menu, click Find, and then search for the key word:

FATAL you might come across an entry such as:


FATAL: SelfUpdate check failed, err = 0x8024402C


...this now gives you something to go on. You can now "Google" this error code to seek further help.

(NB - Start with the last FATAL error code in the log file first.)

You can also do some detective work on the keyword: WARNING

TIP: However, a warning message may not be the reason for any problems you are having so always check for FATAL errors first!

TIP: Your Windows Update History panel may show an error as: 8024402C and your Windows Update Log as: 0x8024402C - they are the same error, its just that one drops the 0x prefix.

...and that is a beginners guide to the Windows Update Log!

More on the Windows automatic updates service.

Kind Regards

Marc Liron

Marc Liron - Microsoft MVP 

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Windows Update Error List!