Thank you very much for your interest in this - I have taken the easy way out and bought a USB printer cable as I needed to be able to print.
However, to answer your specific suggestions:
I did not install any hardware or software around the time when this started - the only think I do not control (and I do not like it in W10) is the OS updates
Anti Virus - AVG
I will do the Windows Update thing, but I will need to find out how to run it manually - I used to know in W7
WiFi adapter will be OK - the PC links to the internet via WiFi
I deleted all HP software and reinstalled it about 2 days ago to see if I could fix the problem - worked when the install was complete, but then stopped
I will continue to investigate, and get back if I find an answer