If things are working fine I would disregard that EV entry. Sometimes things are slow to start and that can cause an entry like that. You could run the Virtual Technician if you like. It may find and fix any errors.
If it continues afterwards, Technical Support may be of assistance. It's free by phone or online chat and linked under Useful Links at the top of this page.
On XP the version of the software is pegged at a slightly older one than what is current and the older versions used to have a feature where the scan would be delayed if the software detected hard drive activity, however, it should eventually start.
Many thanks for the input - put my mind at rest