On a portable computer not all of the automatic updates were successful. There were following errors in the Windows XP's log:
Installation Failure: Windows failed to install the following update with error 0x80070643: Security Update for PowerPoint Viewer 2003 (KB969615).
Installation Failure: Windows failed to install the following update with error 0x8007f00c: Security Update for Windows XP Service Pack 3 (KB973540).
Neither downloaded updates weren't successful.
In the first case I didn't searched for any special solution, but I removed the PowerPoint Viewer 2003 and installed the Viewer 2007.
Another was solved by removing Windows Media Player 11 and Windows Media Format Runtime 11. After a restart, first I installed all of the available updates. Then I installed the Media Player 11 again, and now also the update was successful.