I checked the Windows Update History and there was a 'Mar 2014 Root Certificate Update For Windows XP' (KB 931125) that 'was' installed on March 11th...
You didn't mention this in any of your previous replies. As long as the Mar-14 update was installed, don't worry about the Nov-13 update.
You also didn't tell me you'd replaced MSE with AVG Free (though posts in your other threads suggested you may have done so). Answering my questions would have saved both of us lots of time & grief.
If MSE's no longer installed, ignore the Defs update error. That being said, there's a very strong chance the MSE wasn't installed or working properly. If such is the case, chances are the same applies to AVG & any other AV app you chose to install.
Defraggler vs. WinXP Defrag tool is OT for Windows Update forum.
You mentioned that the 'BITS' thread has not been 'Marked as Answered'-How can I check if a thread was 'Marked As Answered?"
My mistake (and partly yours, too). That thread's in a DISCUSSION forum, not a QUESTION forum. By definition, there cannot be an ANSWER post in a DISCUSSION forum.
That being said, neither http://answers.microsoft.com/thread/3f310847-1919-414a-87bd-76b8b4f6e71b nor http://answers.microsoft.com/thread/8733b2fd-89a3-4503-8ac8-9a6ca1a298a1 have ANSWER(S) post(s).
Keep in mind that there won't be anymore updates for WinXP after 08 April 2014!
• What is Windows XP end of support?
http://windows.microsoft.com/en-us/windows/end-support-help
• The risk of running WinXP after support ends on 08 April 2014
http://blogs.technet.com/b/security/archive/2013/08/15/the-risk-of-running-windows-xp-after-support-ends.aspx
• Microsoft security research paints bleak picture for XP users after 08 April 2014
http://www.zdnet.com/microsoft-security-research-paints-bleak-picture-for-xp-users-7000022537/
• Help your friends and family get off WinXP
http://blogs.windows.com/windows/b/windowsexperience/archive/2014/02/06/help-your-friends-and-family-get-off-windows-xp.aspx
• Cyber threats to WinXP: Guidance for Home Users & Small Businesses
http://blogs.technet.com/b/security/archive/2014/03/24/cyber-threats-to-windows-xp-and-guidance-for-small-businesses-and-individual-consumers.aspx