Nigel
Please run the Windows Update Troubleshooter:
http://go.microsoft.com/?linkid=9830262
All the issues in the CheckSur log relate to the Windows Update Agent If my previous suggestion does not work try the procedure which follows:
Restart the Windows Update service. To do this, follow these steps:
a.Press the Windows logo Key+R to open the Run box.
b.Type services.msc in the Run box, and then press Enter.
c.Right-click Windows Update in the Services management console, and then click Stop. If you are running Windows XP, right-click Automatic Updates, and then click Stop.
d.After Windows Update stops, right-click Windows Update, and then click Start. If you are running Windows XP, right-click Automatic Updates, and then click Start.
Wait for Windows Update to start, and then verify that the Windows Update Agent is updated. For more information about how to check which version of the Windows Update Agent is installed, go to the "How to check which version
of the Windows Update Agent is installed" section in this Microsoft Knowledge Base (KB) article
http://support.microsoft.com/kb/949104/en-us