Good news, it would appear that I've fixed the problem.
Working through 'Outlook doesn't start | howTo-Outlook' suggested by JMH I determined that it was an add-in that was affecting it, namely the Kaspersky Outlook Anti Spam Addin - mcouas.dll.
I've now disabled it and all seems fine. Being ignorant, what effect will this have on Kaspersky?
Once again folks, thank you for your assistance - it's been a great help, and tutorial!