Hey Shaun,
Curious is this your full post of the MGA Diag? If so then the issue may be with your XML services on the computer. Lets try this first but there may be a problem with Windows Update for your computer. If you compare your Diagnostic Report to others on the forum, you will notice that yours is missing a bunch of text below the "Office Details" line. We commonly refer to this area as the XML blob. This is caused by a missing Registry Key and is most likely why the Product Key Update Tool did not work.
I will provide you the steps to resolve this XML issue, but I strongly suggest waiting for the Windows XP disk, that we have sent you, and conduct a clean install.
Fix (Part 1):
1) Click “Start” button, then “Run”
2) In the Run window, Type: regsvr32 msxml3.dll <Click OK>
(Note: This will register the msxml3.dll and the registry entry ‘HKEY_CLASSES_ROOT\MSXML.DOMDocument’ will be generated)
If this does not work, the msxml3.dll may be missing or corrupt. Follow the below Fix (Part 2), in that case:
Fix (Part 2):
1) Go to the Microsoft XML Parser (MSXML) 3.0 Service Pack 7 (SP7) download page at: http://www.microsoft.com/downloads/details.aspx?FamilyID=28494391-052b-42ff-9674-f752bdca9582&DisplayLang=en
2) From the files available, download “msxml3.msi”
3) Double click the file and follow the steps to install.
4) Click “Start” button, then “Run...”
5) In the Run window, Type: regsvr32 msxml3.dll <Click OK>
Take care and let us know if this solves your situation :-)
Stephen Holm
WGA Forum Volunteer