Cant print to HP Photosmart 6520 from any printer

Rufty1

We have had this printer for several months and up until last week had no problems at all. I have an I7 PC specialist built machine and my hubby has a similar Acer. Both running windows 8. Last week my hubby found that when he tried to print the printer was 'not connected'. But when he tried to connect he lost the network connection to the PC. Rebooting didn't solve it, nor fiddling for hours. But my PC was still printing.
Today I scanned from the printer to my PC no problem. But now I cannot print either. I try to connect the printer but then cannot be connected to the network at the same time.
What can we do? On the screen of the printer it is saying all is fine and it's connected to the network, but it's not connecting to our PCs anymore.

forgotmyname

Restore to the default factory setting and go through the setup again.

Both using the same AV and FW? Updated them recently?