Sometimes Windows Update can do strange things. One of them is to offer you the message "Software Update Incomplete". Below this message is generally the subsequent statement:

The Windows Update software did not update effectively.

Send error number to Microsoft: 0x800B0004

The aim of this article is to help you solve this 0x800B0004 problem and have you updating your Windows XP Professional or Home Edition computer
As soon as possible!

Here's how to fix the 0x800B0004 problem:

Step 1)

Did you allow the Microsoft Trust Certificate on visiting the Windows Update website? If you did then move to Step 2.
(The Microsoft Trust Certificate appears when you visit the Update site. If you allow the first time you visit, then you must never have to again. If you have been using the Update website proceeding to this existing problem, then this is doubtful to be the reason of your problems.)

Step 2)

Next we just have to confirm your Internet Security settings are not set too HIGH.

To do this:
Click Internet Options on the Tools menu in Internet Explorer. On the Security tab, click the Internet zone and make sure the setting is Medium.
Now click the OK key, close up the Internet Explorer.
(You might like to have a High setting here, but Windows Update will not work.)
Now open Internet Explorer and try the Windows Update site again.
If it not succeeds with the 0x800B0004 error again try Step 3

Step 3)

In case any of the files in the Temporary Internet Files folder are causing a trouble, let's go ahead as well as erase them.
Click Internet Options on the Tools menu in Internet Explorer.
On the General tab, click the Delete Files button and after that click OK in the small window that appear out.
Now click the OK button, close Internet Explorer.
Now open Internet Explorer and try the Windows Update site again.
If it fails with the 0x800B0004 error again try Step 4

Step 4)

It is likely that a component of the Windows XP digital signatures process is damage - so let’s re-register some DLL files. Sounds like fun, eh? Onwards as well as upwards!

Click Start menu, and then click the Run icon. In the small box that opens, type the three letters: cmd afterward click the OK button.

In the command prompt window that now opened (a black background and white text), type the following commands, pressing the ENTER key on your keyboard after each line:

net start cryptsvc
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
regsvr32 slbcsp.dll
regsvr32 cryptdlg.dll

Now type the word: exit moreover the window will close up. Now restart as well as attempt and respond the Microsoft Patch again.

Restart your machine and attempt Windows Update again. This should now treat your 0x800B0004 error message problem.

IMPORTANT: This article will repair the 0x800B0004 problem for 99.9% of you. But there might be some unusual situation that the reason is a disabled Remote process Recall service or an Active X control issue.