Security Update for Windows XP (KB918439) cannot install

QUESTION:

I was unable to update Windows XP with KB918439 because I used
the workaround option listed below. I used the workaround because
Windows XP Update failed to download the security updates.

How can I undo the workaround to allow the Windows XP update
to install KB918439?

=== workaround is below this line =====================

Type the following command at a command prompt to deny
the ‘everyone’ group access to this file:

echo y|cacls %windir%\system32\jgdw400.dll /d everyone
echo y|cacls %windir%\system32\jgpl400.dll /d everyone

=== workaround is above this line =====================


PROBLEM:

When installing the update KB918439 the following 'Copy error' dialog
box displays the following message:

=== error message is below this line ====================

Copy error

"Ensure that the location specified below is correct, or change it and
insert 'Windows XP System Files' in the drive you specify."

Copy files from:
c:\windows\system32

===== error message is above this line ==================