Sorted !!!!

I ran all the anti-virus programs as suggested - found a couple of little
buggers that are now gone. System is now clean as a whisle.

Then I fixed my windows update and MSN Messenger by doing what someone from
another forum suggested, which is....

Re-registering the MSXML3.DLL
1. Click Start.
2. Choose Run.
3. In the Run box, type: regsvr32 MSXML3.DLL
Press okay

I can now go to Windows Update website and download updates as normal. My
MSN now works as well.

Thanks lads,

Andy J